Outland: a platform game done entirely in silhouettes
Outland is a platform game available on the Xbox and Playstation 3 that is addictive in its content, gameplay, and primarily for me, in the artwork. Done entirely in silhouettes, it borrows from many artistic genres with backgrounds reminiscent of Chinese paintings and baddies that look like Greek warriors.
Its inventiveness lies in the premise that you can switch from darkness to light, opening up different abilities and access to different areas. The game involves mazes and jumping puzzles and increasing levels of skill. Also satisfyingly, at the end of each level you have to conquer a Boss, which I always think is the sign of a good video game.