There've been a dozen discussions on this game already; I'll summarize it all into a few sentences.
Hydrophobia Prophecy is a third person shooter/platformer that was originally an XBLA game, now ported to PC. It's very short, not very great, however it still does a few interesting things. It's not a spectacle of game design, but not really a turd either... just "ok." Certainly worth trying for only a buck and change.
Graphically it's nothing groundbreaking, although, the water effects and physics are quite impressive (I would hope as much for a game called Hydrophobia). There's lots of water involved. And stuff.