Very much potential, but doesn't live up to the hype at all.
The single player game is decent. The whole gravity stuff and portal stuff are cool ideas and seem pretty cool at first, but rather shortly you'll notice those couple things aren't really any thing special. They don't really change the game experience a whole lot. There is also the Spirit form where Tommy (You) goes into a spirit form with a spirit bow. Personally I really like this about the game, especially for multiplayer, but still it doesn't change the game experience a great deal. Just feels like there is so much more they could of done with those few interesting ideas. Anyways the single player is pretty straight forward and easy. Only about a 6-10 hour long game, so some one could beat this game the day/night they buy it. If not, well it shouldn't take more than a few days (a week at most) to beat the single player unless you don't play the single player much.
Well after the short single player, all there really is left is the multiplayer wich is a HUGE let down! First off the only game modes there is is Deathmatch and Team Deathmatch. Those are just the most basic of game modes for FPS games there is, plus so is Capture The Flag wich actually isn't in this game. Surprise surprise! A game without all three of the basic game modes for a FPS not in the game? Anyways this is one reason why the multiplayer sucks (and it would probably still suck if it had more game modes anyways). The other reasons why the multiplayer sucks... Only up to 8 players..... Lag issues (With 6-8 players in a game it will usually lag so much that it isn't playable really).... Lack of weapons as you only got the same ones that are in the demo of the game.... And lastly.... For the most part all the maps kinda seem alike.
More on the maps.... They all are different in a way ofcourse, but each still don't feel that different. This maybe mainly cuz this game is just pure run & gun. Still each map has some thing to set it apart from the others, just never any thing really big. Really it doesn't seem like there is a preference towards any specific maps people wanna play at, cuz they do mainly feel the same. Though one map (The "Shuttle 2" map I think it is) has a vehicle you can get in wich just makes whome ever in the craft pretty much being cheap.
Anyways bottom line... Multiplayer sucks for several reasons.
Trying to keep this short all I'll say about the audio and graphics is that they are both pretty good.
Overall this game is decent, but as some one who has been playing FPS games for several years... This is NOT what I look for for a FPS game at all really. A short single player that is easy with a story that isn't that interesting? And a multiplayer with lag issues, lack of game modes, plus other problems? Trust me people, this is a rental ONLY! Hell you can get most of the games experience just out of the demo.