Small dungeon crawler with roguelike elements. You play as a small child Isaac in nightmarish semi-random basement levels fighting some really disturbing monsters. You can develop Isaac's speed, health and damage by finding various power-ups (there is A LOT of these).
Beware, the game is difficult, but very addictive. A full playthrough takes about 30-45 minutes, but usually you get killed before you reach the final level. It took me almost 10 hours to complete the game for the first time.
Side note: game features child abuse and a lot of disturbing gore/violence including blood, intestines, urine, feces.
But to sum up, it's really worth playing (especially at sale prices below $0.99). It's addictive, has a spooky atmosphere and completing the game is rewarding.
GRAPHICS: 8/10
AUDIO: 8/10
GAMEPLAY: 7/10
STORY: 8/10