Gravitron 2 / Gravitron360

A game by Dark Castle Software for PC and Xbox 360, originally released in 2008, with the "360" version released in 2010.

In March of 1981, Atari designer Mike Hally and programmer Rich Adam began working on a concept for a game that combined elements of Lunar Lander and Asteroids. The result was a prototype called Lunar Battle. The game went through a number of design changes, the greatest of which was to reduce the effect of gravity and lower the aggressiveness of the enemies in order to make the game less difficult. The Atari marketing department then changed the name of the game, which was released into arcades in the summer of 1982 as Gravitar.

Unfortunately, the game still proved to be too difficult for most players and was a resounding failure. Rather than the pick-up-and-play style of most arcade games, Gravitar required that players learn the intricacies of the control scheme in order to experience the game properly (and to survive), which meant that players would have to spend several quarters before they were able to truly play the game. Frustrated, gamers turned to other more accessible machines, and most of the Gravitar cabinets were soon refitted with other games.

However, while it was a commercial failure, the game did have a certain allure, particularly given its tremendous amount of depth, and the intricate controls – once mastered – opened up a gameplay experience that was not possible in any other game. As such, it has remained a favorite of hardcore gamers, and has influenced a number of other games, which saw more prosperity on home consoles and computers where there was no penalty for taking the time to learn the controls.

Gravitar was the primary influence for a number of other gravity-based games, most notably Thrust and Oids, both of which were released in 1987. While Oids is gravity-based and shares a similar control scheme with Gravitar, there’s less focus on precision flying and conservation of resources. The primary goal of Oids is to rescue the “Oids” from the surface of the planet. This is done in a similar fashion to Choplifter, where you blast open a bunker and let the prisoners escape. You can land your ship on any flat surface by aiming perpendicularly away from the planet and allowing gravity to take you down, and then wait while the prisoners board your ship. Your dropoff point is a mother ship that hovers high over the landscape.

Thrust goes in the opposite direction and places even more focus on precision flying and resource management. In this game, you must descend through the cavernous reaches of several planets, pick up An orb, and leave orbit with it intact. What makes this particularly challenging is that the orb is connected to your ship via a rigid bar, and it is affected by gravity in the same way as your ship. As such, it weighs you down and can swing back and forth, forcing you to use extra fuel to lift it and to keep it steady. In advanced stages, you even encounter situations where you have to purposely swing the pod or accelerate very quickly so that it will fit through a narrow horizontal passageway.

It is a combination of gameplay from these titles that influenced games such as Solar Jetman, Sub-terrania, Gravity Force, Gravity Clash, the PixelJunk Shooter series, and of course, the Gravitron series. The original Gravitron was released as a freeware game in 2006. The mechanics were refined and the presentation updated for its sequel, Gravitron2, which was released on PC in 2008 and later ported to Xbox Live Indie Games as Gravitron360 in 2010.

From the description:

Gravitron is a retro styled arcade gravity shooter boasting stylized neon vector graphics in which you must pilot your way through some of the most devious terrains ever devised. Destroy subterranean bases and indigenous life forms while avoiding traps and depleting fuel. Rescue stranded scientists and get out of there before the planet explodes.

The controls are configurable in the options menu, and there are 4 possible layouts.

The default control scheme gives you direct control over your craft using the left analogue stick, allowing you to point the ship in any direction nearly instantly, just as in the PixelJunk Shooter games. The alternate scheme allows players the traditional – and somewhat more precise – method of using the stick for ship rotation only. Both control schemes allow you to adjust the sensitivity independently.

There are 4 other functions, which may be mapped to either the face or shoulder buttons:
  • Fire – shoots straight forward. Hold for rapid-fire.
  • Shield – deflects most enemy projectiles. On the Easy difficulty setting, your shield will activate automatically when a projectile is in range.
  • Thrust – propels your ship forward. On the face buttons, this is a digital function and must be manually finessed by the player. On the shoulder buttons, the intensity of the thrust is variable based on how far the trigger is depressed.
  • Reverse Thrust – This is a new addition. It allows you to thrust in the exact opposite direction of your heading, adding strategy by allowing you to land on any flat surface in the game regardless of its position or angle.

Unfortunately, at least in the Xbox 360 version, your control settings are not saved from session to session, so if you’re not using the default control scheme, you will need to manually adjust the controls each time you start the game.

* Xbox 360 controller used exclusively for this section, and the XBLIG version of the game was used throughout.

Like Gravitar, Graviton2 and Gravitron360 are gravity-based vector graphics games that require precision movement. At the outset of each mission, your ship will appear high above the planet and will begin to accelerate slowly downward as gravity’s tug makes its presence known. You have limited resources with which to complete your mission, denoted by the fuel and shield indicators on the upper left of the screen. And, a bonus timer is constantly counting down in the upper right, encouraging you to press forward.

But your mission here is not the same as it was in Gravitar. Sure, there are enemy turrets mounted throughout the level – and lots of other dangerous things – but destroying them is completely optional. Your goals are instead a mix between those of Oids, and those of Thrust. Your primary mission is to descend upon the planet, seek out the reactors, and destroy them. Your secondary mission is to pick the stranded scientists spread throughout the level.

Let’s start with the secondary objective. In each level, there are a certain number of scientists, indicated by a counter on the upper-right. Often you will encounter these scientists along the path as you make your way to the reactors, but in later levels, they’ll sometimes be tucked away in hard-to-reach areas. Rescuing them is entirely optional; however, they do serve 2 purposes. First off, rescuing scientists is the only way to restore your shield energy. Each scientist rescued will “repair” your ship somewhat, resulting in a small – but often crucial – increase in your remaining shield energy. Secondly, you are awarded with a point bonus at the end of each level based on the number of scientists you have rescued, and points are the basis for being awarded extra lives. Bonus points are also awarded for the amount remaining fuel and shields at the end of each level, and the amount of time left on the bonus countdown timer.

Now, the primary objective: destroying reactors. Here again, there’s a counter at the top of the screen that shows how many reactors are in the level. Their number and placement vary greatly from level to level. Early levels may only consist of 1 or 2 easy-to-reach reactors. Later levels may have a number reactors spread throughout the level, or several bunched up together in the deepest recesses of the planet. You are free to destroy them in any order you wish, but there is some strategy required even in this, because once the final reactor is destroyed, you’ll have a mere 60 seconds to get off the planet before it explodes.

Reactors each have their own life bar, showing how much damage you must inflict on them before they are destroyed, but it doesn’t take too many shots (it’s certainly less work than it was in Thrust). Once the life bar reaches zero, you’ll still have a few seconds before it goes critical and actually explodes. This adds a nice bit of anticipation if you’re on the final reactor.

This is the basic structure of each level. Descend into the planet, seek out the reactors, destroy them, and then pray that you have the flying skills (and fuel) to get back out. It’s an interesting dichotomy in pacing, since the descent is often done by inching along, destroying turrets, feeling your way around the levels, and exploring each corner of the caverns. Then, once the last reactor is destroyed, the game turns into a fast-paced race for survival, and you may find yourself banging your ship against walls, thrusting at full speed through gaps, and taking more risks. In most levels, your diligence upon entering the level pays off on your way out, as you learn the lay of the land, remember tight spots, and take down dangerous enemies that might foil your escape. In a few levels, however, you are made to leave the planet by a different route, in which case you must think on your feet ever the more. Unfortunately, the game’s scroll box is a bit to tight as far as the HUD is concerned. It’s fine while making your descent, but your ship sits too close to it when moving vertically, and it can obscure some of the environment above you.

Per the conventions of the genre, you will of course find fuel pods spread throughout the levels, and in most of the later levels, they are absolutely required, as your starting fuel allotment isn’t nearly enough to see you through (your fuel and shield are fully restored between levels). You don’t need to activate a tractor beam to pick up fuel in this game; rather, flying or landing near a fuel pod will start the transfer of fuel into your ship, and the pod will explode once its supply has been depleted. In addition to the fuel pods spread throughout the levels, you will also encounter checkpoints along the way, which can be a real lifesaver given the size of some of the later environments.

One of the primary conflicts in a genre like this is that the player is required to explore the environment, yet has limited resources with which to do it. And so, the developer has to constantly consider how to deal with the fact that exploration can be both its own reward and its own punishment. As a player, each time you encounter a dead end, you realize that you’ve not only wasted valuable fuel to get to that point, but must waste it doubly in order to return. In this game, that conflict is resolved via checkpoints.

The player is given the freedom as to when he activates a checkpoint (some levels have several), and it records all of the enemies that have been destroyed up to that point. If the player dies, he will return to the checkpoint with his fuel and shields completely restored. Given this restoration, the player can certainly use the checkpoint system as a crutch, thus reducing some of the tension. However, given the size of the levels, this type of design decision helps to reduce situations where a player might have to start a lengthy level from scratch. It also keeps the player from being punished too greatly for exploring a dead end or for experimentation, and thus reduces the old-school need for players to memorize every portion of a level in order to be successful. You may also activate a checkpoint after destroying the final reactor; however, when respawning, the game will restore one reactor, so you will need to seek it out and destroy it once again. This prevents the player from using the checkpoint system to defeat the countdown timer during the escape sequence.

The levels in Gravitron2 / Gravitron360 start out pretty small, but quickly become larger and more intricate. As you progress, you’ll be forced into tighter and tighter spaces, which require you to truly master the controls. Eventually you’ll encounter entire sections of the planet that are rotating independently, forcing you to consider your path carefully as the “down” direction is at odds with the level layout. And you’ll have to remember that there might only be one way out of a spinning room, so it’s important that you time your final reactor detonation properly, lest you find yourself trapped. Moving walls also open and close sections of the level – and some of these can be affected by shooting buttons in the environment – but they can also crush you if you’re not careful. Just when you think you’ve bested the most complex and dastardly level design you’ve ever seen, you’ll find yet another that tests your mettle in new ways.

Enemies become more complex as you progress. You’ll start with some basic mounted turrets, but eventually find turrets that move across the ground, turrets that launch homing missiles, standalone homing missiles, and jumping enemies that shoot at you while bouncing around from wall to wall. There are plenty of environmental hazards as well, such as laser beams and floating mines, which can kill you on contact, and gas jets that can push your ship around. Later in the game, you might encounter all of these enemies and obstacles in the course of a single level, and often several types at once. You’ll even have many instances where you’ll have to take on several turrets within very tight confines.

When in tight spaces, you’ll need to make judicious use of your shields. In the Easy difficulty setting, your shields are activated automatically when you encounter projectiles or lasers. But on the Normal difficulty setting, you’ll need to manually engage the shield when in danger. In either case, use of the shield will deplete your fuel. It’s also important to note that enemy bullets are deflected by the shield and will cause damage to whatever they hit. Often this means that you can deflect an enemy’s shot back at it, but it also means that you might inadvertently deflect the shot into a fuel pod, or accidentally destroy a reactor before you had intended. However, this also means that you can fly into a very tight space and let the enemies fire upon you, and many of them will be destroyed by their own shots. The player will be unable to fire for a second or so after deflecting a projectile. It’s also worth noting that the player receives bonus points for destroying enemies, fuel tanks, and reactors with deflected bullets, over and above the value received when destroying them directly.

A number of tweaks have been made to the design that offer improvements over many of the other games in this genre. For one, you now have a REVERSE THRUST button, which feels like a natural extension of the original controls and offers the player a great deal of precision since you no longer have to rotate your ship 180 degrees in order to slow down. Plus, it lets you get pretty crazy with full-speed runs during the escape sequences, since you can mash on the “brakes” whenever you wish.

A secondary function of the reverse thrust is that you now have the ability to land anywhere. In the games that do allow you to land your ship, this must always be done on a horizontal surface on the ground since the player will need to rely on gravity to take him down. Not here. In this game, you can REVERSE THRUST onto any flat surface – even angles – and land your ship. This means that you can park your ship on walls and ceilings, offering precision firing, and allowing you to conserve fuel while you wait for a wall to move, or for an area of the level to rotate, or for a series of laser beams to stop firing. And if nothing else, it gives the player a chance to stop for a moment and consider a strategy before moving forward.

The game also offers a radar system to allow you to see beyond the limits of the screen, and it identifies enemy positions and reactor locations. It also helps you determine where you need to go next and to keep your bearings straight while you’re spinning about. However, the radar is deactivated once the level’s final reactor is destroyed… so don’t forget the way out.

As with Gravitar, you can abort the mission at any time by simply flying off the planet. You’ll restart the level with your shield and fuel restored, and all previously destroyed enemies will still be gone, but your bonus timer will resume counting down from where it was when you left the planet. This is functionally the same as using a checkpoint, except that it doesn’t cost you a life.

There are 44 levels in the main game, with an additional set of levels available in a bonus pack, bringing the total count up over 70. The player is free to start with the standard levels or the bonus pack from the very start, and each has its own difficulty progression, with the bonus pack being the harder of the two. The game is entirely linear; the levels must be completed in order and the player is not given the ability to replay completed levels.

In addition to the main game and the bonus pack, there are also 4 different challenge modes, each offering 5 small levels, for a total of 20. Make no mistake, the challenge levels are hard. It’s very likely that you won’t be able to complete any of them until you’ve spent some time with the main game and mastered the controls. Even then, they’re certainly no cakewalk.

Here, you have to rescue a specified number of scientists in under 60 seconds as the reactor timer counts down to the destruction of the planet. Since each rescued scientist restores a bit of your shields, we prefer to refer to this challenge as the “shields be damned” mode. Feel free to bash your way around the environment and make some hard landings… those scientists will fix you right up. You don’t have to get them off the planet to beat the challenge; you just have to rescue all of them.

This mode has you attempting to complete missions without firing. In order to do this, you’ll need to use your shields to deflect enemy shots toward targets. They’re not easy to line up, but there’s no time limit, so you can keep trying until you deplete your fuel or shields.

Similar to the scientist rescuing game, this one has you activating checkpoints under a countdown timer. What makes this particularly challenging is that all checkpoints rest against a solid surface, and you have to get pretty close to activate one. So, you’re going to do a lot of fast flying low to the ground. Missing one usually means you won’t have enough time to complete the challenge, and flying in too hard may force you to bounce off of the ground. This is a perfectly acceptable strategy for activating checkpoints quickly, but you’ll have to keep an eye on your shields as well as the clock.

This set of challenge levels mimics Thrust, in that you have to descend into a planet, pick up a power orb (use your shield to pick it up), and carry it safely off the planet. If the orb touches anything, the planet explodes. There is one major difference between this challenge and the game of Thrust, however. In Thrust, the tow bar that connected you to the orb was rigid, and therefore the orb always remained at a set distance away from your ship. The challenge was to understand its gravitational function as a weight that affected your ship differently depending on its position in relation to yours. Here, however, the tow bar is elastic, making the orb’s movement much less predictable, since it can swing out into walls, drag behind you when you accelerate, and jerk forward into your own ship. The difference makes these challenges much more difficult.


Orange Missile Turrets There are 2 types of heat-seeking rockets in this game. One has a somewhat loose tracking, while the other comes straight for you. Now, you’d think that the missile with the tighter tracking would be the bastard of the bunch, but it’s not. The reason for this is that the tight-tracking missile is single-use and it can be shot out of the air. Plus it won’t launch until you get into close proximity, which gives you time to take it out from a distance, or at least get your gun pointed at it when it comes your way.

The orange missile turrets, on the other hand, have an infinite supply of missiles. Most of them have a long reload time, but that might not matter to you when you waste that span trying to dodge the first missile as you try to line up a shot on the turret. What’s more, you can’t shoot them down, and they’ll continue to circle around you for a long time before they explode on their own. If they do manage to hit you, they’ll take a good chunk of your shield away and knock you back, which can be a real pain if your fighting them in an enclosed area, since you can be sent bouncing off of walls or flying into other enemies.

Oh, and did we mention that they can fire at you from offscreen? Yeah, that’s right, you might have a missile in your mouth before you know where it’s coming from. And you’d better hope your skills are sharp if you encounter more than one. The developer knew how bastardly they were too, often placing them in strategic positions to guard openings or reactors. You can try to dodge them, but it’s best to get near a wall or an enemy and let the missile crash into that. And don’t forget to aim some pain toward the turret before it can reload.

Laser Beams The nearly ubiquitous video game laser beam was designed to keep you from moving forward. No one knows who put them there, but you can’t pass while they’re turned on. Laser beams appear throughout this game and come in a variety of flavors. Most are stationary and simply engage and disengage periodically, requiring that you to time your movement to slip past. Others require that you shoot a button to disengage them… sometimes only temporarily. Some move back and forth across the floor. And still others are lined up in a row like synchronized swimmers, firing on and off in a beautiful display that acts like a dancing wall of photonic death, allowing you only a narrow window to jet-fire your way through them before they cook your face off.

In Easy mode, your shield will kick on automatically when you run into a laser beam. Saved, right? Well, running into a laser with your shield engaged will bounce you backward, and if you remember your physics, you might recall something about an “equal and opposite reaction”. This basically means that if you were burning your thrusters hard to make it through a gap before the laser turned on, you’ll be bouncing backward extra hard if you don’t make it, potentially ricocheting off the walls like a spaceship-shaped pinball. The lasers can even be problematic if you’re moving slowly, because if you’re right in the center of the beam when it turns on, you’ll be bounced away very quickly. Keep in mind that lasers usually have a lot of friends – who are also lasers – and you could be bouncing around between a whole series of them as they turn on and off.

On the Normal difficulty, they just kill you. There are plenty of lasers in this game, and therefore plenty of opportunities to meet a quick and explodey demise.

There are no bosses in this game. Your greatest enemy is the planet itself.


Why this game should be part of your 2D heritage:
  • Preserves high-precision gravity-based gameplay of several classic games
  • Ability to reverse thrust and land on any flat surface
  • Modern design additions balance large environments with a radar and checkpoint system
  • Dastardly and clever level designs challenge your mastery of the controls

The downside:
  • Doesn’t remember your control settings from session to session
  • HUD obscures environment when moving vertically