While it's a bit peculiar to give GOTYs for a single mobile device, none had as robust a library of games offering as Apple's iPhone and iPod Touch did in 2009.
There are almost too many out there to offer an authoritative comparison of them all. But here are the ones I enjoyed - and played - the most in my first full year owning an iPhone, and they're all laudable achievements in design and gameplay on a platform that is, for the most part, still very new.
2XL ATV Off-Road
I find tilt control to still be a work in progress for many games, but in 2XL's ATV Off-Road, it is expertly tuned, making it one of 2009's top racers. In addition to the controls, ATV Off-Road delivers a console-quality experience, another holy grail of mobile gaming that, while laudable, seems to get in the way of some games more than it helps them. Not here. You're given arcade and career modes for your racer, untimed freestyle tracks if you just want to jump off cliffs and land tricks, and best-in-class visuals. There were many ambitious attempts to deliver core gaming on the iPhone, and ATV Off-Road delivered on that potential the most.
Another early review that still manages to entertain me nearly a year later. Dapple is a knockout puzzler with a mixing paint theme - blend two colors to create a third, and use that to knock out four or more adjacent pieces of the same color. I earlier knocked the game's randomness but after playing it several dozen hours I can see its necessity, otherwise you might keep playing forever. The timed and untimed modes and varying difficulty levels deliver solid replay - indulging either long time-killing stretches or short runs at a new high score. The colorblind assistance mode is also shrewdly constructed and a wonderful gesture by the creator. Yet even as a colorblind gamer I can play its standard mode for an hour, never feeling at a disadvantage.
Canabalt's port to the iPhone extended the one-control indie sensation to the platform perhaps best suited for it. No accelerometer, no color, no console-quality graphics, no complicated multitouch, just dazzlingly addictive, never-ending gameplay set to a righteous soundtrack accompaniment. I saw a guy playing Canabalt on a flight, asked its name and didn't even have to write it down, it was that memorable, just watching it from across the aisle. In the end, you know you're never going to outrun, well, whatever it is you're running from. But the feeling - the certainty, actually - that you could have lasted just a bit longer always brings you back for more.
Edge by Mobigame
The Tim Langdell controversy is irrelevant to this award although some will certainly view it as playing a role in my decision. It doesn't. I reviewed Edge two months before the shenanigans broke, and at the time called it "a must have game, moreso than any racer or puzzler out there." I still feel that way. And I believe Mobigame's fight with Langdell over the right to publish a video game named "Edge" struck plenty of nerves because it was such an exceptional game.
Edge, an isometric platformer in which you manipulate a cube through obstacles and past traps, is a triumph of design, in both visual aesthetics and gameplay. It absolutely is an homage to 1980s games like Marble Madness (or Crystal Castles), but carries enough quirks and varying objectives to remain very much its own game. The three means of control - accelerometer, touch-and-drag, or virtual direction pad - are a genuine gamer assist, making it accessible to gamers of all skills without condescending to them. On top of all that, the soundtrack by Romain Gauthier, Simon Périn, Jérémie Périn, Matthieu Malot and Richard Malot is one of the best of any game - on any platform - of 2009.
Edge has been removed from the U.S. app store twice and it's not currently available for download. So it is a special game, indeed, to see its icon in your iPhone and feel fortunate to have gotten it before it was taken away.