Just stop and listen for a moment, in-game.

Hear anything?

Actually, a destinct lack of something: Music. This is the only game that gets away with having zero musical score, just by being so damn atmospheric you don't even <i>notice</i>!
Also: Level design is great: Seeing bits of the castle in the backround really give you a sense of knowing where you're going. It really does seem to all link up.

Taking the chunk of wood to those demons who try to cart away Ico's girl there is one of the most satisfying things I have ever done in a video game. I only wish real life were so simple and so gratifying in that manner.

This is also one of the ten best games ever made and really reminds me why "adventure game" is my favorite genre. I admit, I had been wondering if it truly still was for me. It had been a while since I had played an adventure game this fun. Wow.