Endre Barath's Dead Cyborg is a first-person puzzle adventure game based on a free, donation-based model.
It's not open-source, but it runs perfectly on Linux.
Dead Cyborg can be downloaded from the site (I recommend version 002 as it supports mouse look instead of just the arrow keys). To get it running you simply extract it and run one of the four bash scripts provided depending on which suits your needs. The game ran flawlessly for me on both Linux Mint and Arch (there is a package available in the AUR).
You start the game waking up in some sort of cryogenic freezer, not knowing who you are or how you got there. As you advance you read messages left behind by your colleagues who had ventured out of their capsules some time earlier, before their deaths at various stages along the way due to radiation posioning. Of course, they somehow managed to lock all the doors behind them and un-solve all of the puzzles. Ah well. The atmosphere is somewhere between quirky and grim.
It looks gorgeous. The graphics are detailed, there's a consistent visual style, and there's a nice big font for dialog. The animations are few but quite nice. You can tell a lot of time and care has gone into crafting the game world.
It doesn't take long to notice that the gameplay in Dead Cyborg is quite simple and isn't going to vary much. It is essentially a game about searching for objects to interact with, some of which are very well hidden. The majority of your time in the game is spent walking around trying to find objects you don't even know you need. There's not much logic involved in solving a lot of the puzzles. Items can be picked up, but not combined, so the combinations of actions that can be performed are severely limited. Often you find yourself moving around with an item active clicking everything else you see in the hope of getting a reaction other than the stock "I don't think that's a good idea" and an irritating beep sound.
This isn't necessarily a bad dynamic, though. Since the first Resident Evil clones in the late 90's, games of this type have been criticised as badly-designed because of the illogic of the puzzles. Games like Ico, and more recently the Uncharted series, wind the puzzles into the experience and game world so tightly that the player knows exactly what they have to do in a situation, and the gratification comes in finding a logical solution. But it's a testament to Dead Cyborg's "find keycard A to put in lock B" style of gameplay that it survives today and can still serve up an addictive and rewarding experience such as this.
Dead Cyborg is difficult, and advancement is limited to extremely small steps. As soon as one obstacle has been overcome, another one is presented almost immediately. But you don't want to give up.
The game is nicely structured. It's subdivided into a series of levels. There is no save system; you pass certain areas, you are locked out of the previous area and given a password to return to this point if you quit the game. It's a clever system that works really well.
Dead Cyborg is a great experience. It's free, and the artwork and atmosphere it offers are enough to make it worth checking out even if the gameplay doesn't tickle your fantasy. It's a weird, dark, technically interesting piece of software.
The ending which I won't spoil is quite exciting and has me looking forward to episode 2. There's a trailer out and it looks even better than episode 1.
