I don't have a PS3 but i've heard great things about Journey and the overall experience outweighs the short game length. I'm not even entirely sure exactly what style of game it is.
If anyone is looking for a cheap and reasonably expansive gaming experience, check out Dust: An Elysian Tail. It's an arcade title (not sure if it's on PS3) and it was just phenomenal. It's only fifteen bucks, it's anime style which I am not a fan of but I got completely sucked into this game. It's a side scrolling RPG similar to old Castlevania games, and everything about it is amazing. One guy developed it completely by himself and it was originally an "indie" game brought to life because of how great the final game turned out to be.