I'd give Vessel a solid 7. The music and art is great and the puzzles are fun. Points off for it being a bit short, even if 7 or so hours for $15 is a good value compared to most FPS campaigns. The shortness also detracts from the upgrades you can acquire by spending upgrade juice you get by solving optional puzzles and from finishing levels. Seeing as none of them are necessary to complete the game, and there's very little "combat" in the game for them to be useful, they're a wasted opportunity.
I should not walk so a child may live.----http://www.spore.com/view/profile/Catsimboy