I finished Ico last night and was completely blown away. At first, I was extremely annoyed with the controls, and the combat. I had to keep reminding myself that the game was over a decade old, and that some of the mechanics may not be as smooth as modern day titles.
On the other hand, the setting was intriguing, and I felt like I had to keep exploring. I love how the game never tells you what to do. It so well designed that it doesn't need to explain itself or give you hints. I liked that there wasn't a life bar or anything else on screen to clutter up the experience as well. The lack of dialog really had me thinking about the story, and where it was going as I was playing.
After getting used to the controls and upgrading my weapon, I couldn't put the game down. Ico is a truly amazing game.