I can't believe the incredibly low-score Erik gave Messiah.
Possesing a character after which you'll be able to walk along their species without them knowing who you really are is just plain awesome. There are quite a lot of different life forms to posses, from giant mutants trained by the cop, put into a heavy armor with build-in rocket launcher and infinite machine gun to Pimp Daddy.
I haven't noticed any laggs at all whilst playing this game and the graphics aren't that bad, Erik must've been playing this game on a quite slow computer whilst reviewing this game.
The guns. The guns are fun to use, but easy (gunfights with multiple enemies can be a pain in the a** tho). The melee combat is fun :) You can snap people's necks by sneaking up to them or a special melee cop-unit has a weapon which is basically an electric-stick without any electricity needed, it stuns after just one hit so it's better if your try to avoid getting close to them (they have flash grenades and they have a special shield too whilst crouching).
Talking about guns, there is one AWESOME gun. The Harpoon Gun, you can shoot people, after which they travel with the harpoon through their body until they hit a solid object (wall/pipe). They'll die quickly or they'll still live for a minute or two, their pain screams are satisfying, very, very satisfying. It just scares me of good it feels XD
This game is dated, and rather short (It's not very short but when your done playing, you'll just wish the game was longer). There are multiple difficulties, The hardest one is really hard, whenever your host dies in any other mode, Bob will just jump out. But if your host dies in the most difficult mode, Bob will die too. You'll most certainly die if you end up in a gunfight with 5 cops with machineguns. If you manage to press backspace (or any other key mapped to the "jump-out" animation) and Bob jumps out, you should make sure that you have the ability to posses another host soon or run.
This game is really awesome, better than most of the P.C. Games I see these days. You should try to get your hands on this, It's really worth it.