It's been called the spiritual successor to Ico, but if you haven't heard about it, here's a look at Rain
. Rain is a story of an invisible boy who can only be seen when the rain falls down in the world. He finds another, a girl, and both try to survive together in a world where they are hunted by monsters.
It's a pretty interesting and solemn trailer, showing you some of the puzzles you might encounter. The rain effect is OK as they seem to be more ghost like to me then being rained on. For those looking for something original to play, Rain might be up your alley.