I was lookin' forward to this one: Abuse is a dystopian sci-fi sidescrolling platformer. It is the opposite of Sudoku. You play a dude who was wrongfully imprisoned in the kind of prison you don't want to be wrongfully imprisoned in, i.e. one where they perform experiments on the prisoners. Thanks to an ill-timed riot and (presumably) an accident of some sort, everyone in the prison except for the player-character gets infected with a drug called Abuse that makes them batshit-insane and also makes them look like they were designed by H.R. Giger.
There are two types of open-source games, generally speaking: games which were developed by the open-source community, and games which were originally developed for retail sale, and eventually had their code released. This is one of the latter - Abuse was a quasi-successful game back in the dizz-ay (1996), and at some point later on in the 90s, they released the source-code. What I'm trying to say is that this is not a game that was recently released; I don't think it's even been worked on in a number of years. The game is basically unchanged from the original 1996 version, and hasn't been touched at all since 2000, near as I can tell.
Art-direction wise, it looks pretty good considering the state of the art at the time. The graphics are a bit pixellated but they manage to convey the creepy sci-fi vibe that they're undoubtedly going for, and it has a cohesive and consistent look. The game basically looks exactly like a Genesis game I played back in the day, based on the Alien franchise. Which is high praise for a shareware PC game.
Sound was the first problem with the game. I installed this from the 'Add/Remove...' option on the 'Applications' pull-down, not from the more powerful 'Synaptic Package Manager'. I will be doing so with all of the games I look at. The sound didn't work. So I looked at the entry again, in the list of available games, and saw no mention of it needing extra sound-files, as some websites seemed to suggest. This lead me to assume that it was a complete installation, and the problem must be with my soundcard.
After hours of struggling, I managed to confirm to myself that my soundcard was working perfectly, and so I looked in the 'Synaptic' manager, and saw a sound-pack for the game. So much wasted time... but worth the effort, nonetheless. Laser-guns are much more satisfying when they make that zappy sound, and hearing creatures before they show up onscreen makes for a useful warning.
Control-wise, the game is almost as broken as Gnometris. It's got a relatively novel system of mouse-keyboard support, where your mouse aims your weapon independent of your movement, which is controlled with the keyboard. Only, for some reason, it's difficult to shoot straight forward to the right, and virtually impossible, to the left. Even when your gun is pointing straight ahead, and the cursor is directly level with it, the gun likes to shoot toward the floor and rebound.
The main effect of this problem is that if an an enemy is above you in a narrow corridor, you can shoot it with no problem. But if it's standing on the ground right next to you, you shoot the ground, and the laser rebounds over its head. So you basically have to either move closer to it, taking damage, or hope that it will jump up into your shot. This is bad enough when there's just one enemy on the screen, but when you're being chased by four or five speedy little buggers at once, it's insane. My general strategy when being chased by things is to back away while firing, but that doesn't work when firing at things that are chasing you is impossible.
So the game is basically unplayable. I couldn't find any mention of this anywhere else, which means that either I'm the only one with this problem, or the game's just so old that no one plays it anymore. My guess is that the libraries the game relies on have changed in some way since the game was being actively developed, and one of those changes broke the aiming.
I tried switching from software-rendering to OpenGL mode, which took a lot of work to get working (what finally did it was reinstalling the restricted nVidia driver), in the hopes that it would fix the problem, but it didn't. It was still impossible to shoot anything that was next to me on the left, and virtually impossible to shoot anything next to me on the right. You would think that placing the cursor directly over the creature, at least, would work. No dice.
The game looks better without anti-aliasing on, in my opinion, as the anti-aliasing just makes everything extremely blurry. So keep that in mind if you're going to try it out. This game was probably awesome when it came out, but if it's as non-functional for you as it was for me, it's not even playable. This is a shame, because it seems pretty neat. It offers infinite lives, and you restart after death from the last save-point, so you can still brute-force pretty effectively by replaying spots until you get lucky and the monsters get into the areas where you can shoot them, but that takes an awful lot of effort.