Fumito Ueda's hyper-sensual debut is the most influential single player experience of the 21st century. While Ico may have adapted Out of This World's style of puzzle-platforming gameplay from a decade prior (taking it from 2D into 3D), its most unprecedented innovations actually lie in its immersive value.

Here's a bold claim: Ico is the first 3D game with fully believable animation. It's difficult to believe that characters designed and animated at the turn of the century, appearing first on sixth generation hardware, manage to be so captivating in their motions. Yorda patting a save bench in hopes that you'll come sit with her is one of countless soaring moments. You'll believe she really was there and gesturing to you, not merely conveying some mechanic you need to make use of. There's nothing uncanny about it at all. Ico is a purely interactive experience, so almost nothing that happens in the game registers in the mind as text or 'concepts'. It all must be felt to be processed, and it never seemslike the game design is punishing your progress despite how uncompromising it is.

Also worthy of note, Yorda being older than you (or at least taller) prevents the game from seeming like it can adhere to a standard otaku fantasy. Yorda must be protected, but you'd have to be pretty depraved to desire possessing her. After all, the first thing you do with her is break her out of a cage.