Around the time I was in middle school, probably sometime before that, my favorite computer game was a game called Greebles. The name Greebles has as its background image the 2d fly and on the title screen lots of dark colors blues and blacks. The way the game works is that you are a tank 1×1 size on a 2d grid around 20 by 20 squares large. In the grid a maze is generated and within the maze there are enemies that are also 1×1 first starting with flies. On these first levels there are flies but on later levels there are all manner of enemies and enemy generators.
The key thing is that as a tank you can move at a normal speed around this maze and the bugs are also moving normally. By pressing the space key in the direction of a wall of the maze, the wall separates into a block that flies in the direction that you are facing. If that block hits a fly the fly collects on the side of the block along with any other flies. Against enemies, the collision is inelastic and when the block hits a wall on the other side the flies are squished and you get points with a convincing splat. When the flies are hit sometimes they spin and pileup in front of the block.
One of the first big mechanics is bomb blocks. When you propel a bomb block, you don’t need to hit other enemies to kill them. If a bomb block hits another bomb, they both explode, which in this case means, there is a loud bang and the blocks disappear. Any bomb blocks touching each other explode. Any blocks in the vicinity that are not bombs but have the ability to be propelled go in the direction the bomb exploded like shrapnel. Any enemy or ally including yourself that is adjacent to the explosion dies, this time blinking out of existence. I believe it is also possible that there is another block that is like a bomb block that is more sturdy that is on a timer, so it is possible to propel by a bomb block into another bomb area, thus the initial bomb triggers a chain reaction. It is possible to destroy a lot of enemies not only from the bomb but secondary effects like blocks being propelled. It is a common trick to shoot a bomb block down a hallway which will explode, disintegrating any block, another mechanic that cannot move, and propelling the blocks that make up the dead end down other hallways into other enemies.
If you are at the end of a hallway and an enemy is coming for you, you can propel blocks and try to make an escape. It is also possible to chomp blocks, although it takes some time to make them disintegrate. It might not matter though because on the opposite side there could be more Greebles.
There are a few special blocks. One of them you disintegrate and freezes enemies, another speeds you up, and another makes you invincible: I believe it is called death touch. There is also some money which doesn’t do anything I think just points, and extra lives. In later levels, Greebles are generated on a clock by generator blocks every 10 seconds or so. One way to destroy these generators is to surround it by ordinary blocks. When you propel a block sometimes it hits a wall and the collision is elastic, so the block bounces back. I don’t think it is harmful usually and you can ram into the block and push it into position. If a block is propelled by an explosion though I think it might kill you, or perhaps it just bounces off of you harmlessly. When the clock goes off around a surrounded generator it disintegrates. There are also in later levels blocks that don’t move and generators that don’t disintegrate. The game can become very difficult by developing more and more enemies with different features. Some are very fast. Others could be smart. Some on splatting might explode. I think around level 70 or so there are some that when you make splat create generators, so if the generator is not against an edge, it will make more. It was a high level. Also, perhaps there were some that on splatting turned into generators for other enemies like chess pieces which did not move in any new special way, maybe a bit faster with some acceleration. There were some really tough levels I believe with generators that could not be destroyed, if you surrounded that they simply ejected the blocks in all directions in lieu of creating new greebles. Some of these generators also just wore down I believe and if you survived long enough you got to go to the next level. The toughest levels had a lot of different blocks and enemies moving at fast speeds, and just to survive you had to dodge a lot of stuff. Some enemies could even propel blocks themselves. When you defeated all the greebles you could go to the next level.
The game had multiplayer and network play and I remember playing some with my brother on the same keyboard. I really liked the maze aspect and block activity, the grid, and arcade style of it, sort of like Pac-Man but you had more options. The sounds and general vibe of the game, difficulty & colors, were pretty good too.