I've actually played relatively few computer games this year, mostly because my chair for my desktop PC is still broken, and my laptop is a MacBook (and therefore suffers from neither being Windows, nor having as up-to-date versions of Wine available for it as Linux-based systems). This gaming review of my year, therefore, is based almost entirely upon games I've played in the last two months (most of the games here were bought in one or other of the Humble Indie Bundles recently), or one game for Nintendo DS that I finally got around to playing (mainly due to finally having a DS Lite).
I've also not actually finished most of the games here; the ones I've completed at least once are Portal 2, SMT:SJ and The Binding of Isaac. (I've not mentioned games here that I've not played at all, but own. This is mostly the additional games that comprised the Humble Bundles, but also Deus Ex: Human Revolution, which I'm still waiting for the OSX port of...)
Shin Megami Tensei : Strange Journey (Nintendo DS)
(the first game this year to reduce me to tears (at the conclusion of the Neutral ending); also the game I stopped playing on New Game+ as Lawful, because you're forced to be such a horrible person that it was sapping my will to continue. Not released in the UK: I picked up my copy in the USA last year, in anticipation of buying a DS at some point. )
Marathon (technically: the remake of Marathon in the Aleph-One open-source engine).
(Very very hard to play with a trackball or a trackpad. As a result, I've not managed to get past the first level, embarrassingly.)
unrated: not enough play time.
The Binding of Isaac
(Ed McMillen's games always have the problem that Ed has the sense of humour of a dysfunctional 12-year old. This means that the tone lurches between toilet humour and something approximating darkness, which can be mildly off-putting. Danny Baranowsky's soundtrack is the best thing about the game; the gameplay is the second, combining the best bits of Zelda, Robotron and the roguelike genre to produce something almost as good as one of them.)
Super Meat Boy
(not as "hard" as it might be, which is not necessarily a bad thing; what is less forgivable is the terrible performance and surprisingly high system requirements. Once again, the main reason to play this is Danny Baronowsky's excellent music, especially if you have the poorly ported OSX release as I do.)
Cave Story +
(a platform "rpg" which really wants you to use adjectives like "enchanting" about it. I particularly like the experience mechanic - unlike most games, it's your current weapon which powers up with experience, not you (although additional health is available separately), and is depowered by taking enough damage subsequently. In terms of tone, it's towards the cutesy end of Japanese RPG design, with anthropomorphic bunnies as the majority cast members, other than the player.)
(like Portal, one of the few Valve games to throw me out of the naturalness of following the path (both games have moments where you're forced to do something obviously stupid to make the plot continue), a bit easier than Portal but also more varied (partly because it actually tries to have a plot, partly because of the new gameplay mechanics introduced), I didn't play the co-op mode because I have no-one to play with (which is one reason I took so long to buy this in the first place; also the other game that brought me to tears at the end)
(one of a series of games in the Bit.Trip sequence, RUNNER is basically Simon, but with platforming: Captain Video must complete a series of auto-scrolling levels by performing the correct sequence of actions (jump, slide, kick, etc), in time with a musical background. Notable mostly for being one of the cluster of inter-pollinating Indie games of the last few years, RUNNER featuring guest characters from other games, and Captain Video likewise guesting in others (like Super Meat Boy)).
(a bullet-hell vertically-scolling shooter set in a steampunk world where we colonised Mars and the Spanish allied with the advanced Martian civilisation for Evil purposes, and with an excellent soundtrack,.What's not to like? Shop-based unlockables are also well implemented. )
Crayon Physics Deluxe
(a winner of the Independent Games Festival, based on drawing freeform solutions to physics-based problems (in each room you have to get a ball to a star. Everything you draw becomes a rigid physical object, which you can use to solve the room in whatever way you wish. Despite this, the form is a bit limiting, and the game quickly feels a little restrictive, especially when it fails to interpret your drawings correctly.).
(another prize-winning game, with another simple mechanic: Captain Viridian stars in a 8-bit styled platformer where, unusually, you cannot jump: instead, you can only invert the direction of gravity while touching a surface. The restriction provided by this is the source of multiple puzzles, many of which require you to "fall" through multiple rooms before reaching a terminal surface on which to launch yourself from in the opposite sense (often in order to accomplish a total horizontal movement of only a few blocks width over a deadly obstacle). Like Super Meat Boy, death is cheap, and twitch-sequence learning is necessary; unlike SMB, VVVVVV is consistently likeable, if surreal, and performant on basically any computer.)
Edited post-25th Entry:
Gratuitious Space Battles
(GSB is Positech's interesting approach to a space tactical game, focussing on design, rather than control. Given free-reign to design ships, their deployment, and their initial orders (such as: escort this vessel, fire on any enemy attacking this ship), each battle consists of the action unfolding without your further involvement. There is an unlockables system, paid for with points awarded for how well your designs have done in each engagement (winning significantly under budget gives more points). Limited by the available number of missions, and by a difficulty cliff at the start of the game (you'll lose most of the time when you start playing, until you start to understand how the game mechanics work).)