The words I'd use to describe Ico are 'Monumentality' and 'Wonder.' The Castle fills me with a sense of both; being able to see places you've been and will go to, as tiny parts of a much larger map fill me with the feeling of how big this palace really is. Seeing the Windmill from the Eastern Gatehouse specifically made me gasp, just a little bit. Wonder is also a very prevelent thing in the game, wonder at what this castle used to be in its heyday, what the shadows were, who Ico was, and where he came from; it inspired me with an imagination, and made me really think while exploring. Ico makes you wonder a lot, and makes you think, but in the end it is an amazingly fun game, which is I think, might be the whole point.