If you liked Riddick EFBB then you'll love this game
I got it earlier this week, I hadn't read a single review or anything I simply bought it because I'm a fan of Starbreeze's previous work.
I was quite pleased...
Graphics
I'd say graphically the game is a high 8/low 9 On a while they're amazing... but it starts to lose a little quality in the details background textures like signs and such are low res, which wouldn't be so bad but there are often times you're required to look at a map on the wall or a room number and it'll be all pixelated and ugly. the game features self shadowing which is awesome graphically but it flickers sometimes. Again this would normally not be noticeable but the loading screens are close ups of your character narrating the story and when his face takes up the whole screen and you're watching his nose shadow flicker on and off his cheek it can be rather distracting. If those two issues were fixed I think the graphics would be a 10... the lighting effects normal mapping character models animations and textures are all top notch. My brother stopped by my house half way through the game while there was a cut scene playing and he seriously thought it was a live action movie for a few seconds
He's a gamer too just to put it in perspective.
Plot/Storyline
This is where the game shines... IMO it could be quite possibly the best storyline of any Xbox 360 title to date. The characters are all really well developed the voice acting friggin rules (particularly the Darkness and Jacky) and there are quite a few side quests and loads of hidden stuff. Also the game is rather open ended... there are a number of areas that make up the city and you can pretty much go anywhere you want when you want. The storyline is linear but you can usually break away from the main story and work on side quests or hunt for hidden items, just explore the world whenever you want.
Gameplay
The gameplay is great too... switching between darkness powers/weapons can be a little clunky but most of them are not used for the heavy action stuff but getting through areas where you need to unlock a door from the other side or move some large object. The darkness guns and black hole can be quite handy as sort of an alternate weapon when doing battle with baddies in the game. In terms of the gameplay I'd compare it more to Condemned than a typical FPS. that is to say it's not as fluid or fast paced as your halos or Gears... it's a story driven adventure first and an FPS second. I should note that I haven't yet played online
Replay value
You can play through the solo game in about 12 hours time, but there is enough hidden stuff/achievements to easily warrant a 2nd play through and the story is good enough that you'll WANT to play through it a 2nd time. There is also a multiplayer mode which I haven't played and I heard it can be really fun but it's horribly laggy over xbox Live. It does offer system link play though and from what I hear that plays much better than over XBL. There hasn't been any game updates since it's release and the rumor is that one is coming to help reduce the XBL lag.
My advice:
If you're not interested in the online you can get away with a rental... but I love the story enough that this is a game I can see myself playing through a number of times.
overall I'd give the game a solid 9/10
I think they would have been better served adding more to the single player experience (like 4 or 5 more chapters/ 10 or so more side quests) and getting rid of the multiplayer altogether but the game that is there is quite worth playing.