Hotline Miami is a 2D top-down action video game by Dennaton Games, a team composed of Jonatan Söderström and Dennis Wedin, who had previously collaborated on Keyboard Drumset Fucking Werewolf. In the game, you take the role of a mentally unstable hitman in 80's Miami. Urged by cryptic messages on his answering machine, he goes out to kill mafioso while donning an animal mask.
Each level of the game puts the player against a large number of armed foes dispersed throughout a building, which the player then must use stealth, wits, and lightning-quick reaction to clear out. The enemies all die in one or two hits, but so does the player character. However, the player can instantly restart the level to try again. The more inventively, quickly, or brutally you can finish a level, the more you are rewarded with unlocked weapons. Throughout the game, you can retrieve more animal rubber masks, which each give you a special ability.
Hotline Miami received both Eurogamer and Rock, Paper, Shotgun's Game of the Show award at their inaugural Rezzed expo.
Source: Wikipedia, "Hotline Miami", available under the CC-BY-SA License.