My take:
[EDIT]: sorry for the confusion... dunno how i forgot to mention this review is for the xbox 360 version. however, i'm a sure a lot of it will apply to the pc version.
=== Graphics ===
Overall, very impressive. In some areas, such as blur, textures, soft lighting (hdr) and character models, these are some of the best graphics you'll find anywhere.
=== Sound ===
Good enough to get the job done. Sound effects are decent, voice acting is acceptable, music is fine. Nothing mind blowing here, but nothing to complain about either.
=== Style/Character ===
The game has some very unique elements it def gets some kudos for. The chainsaw mechanism is brutal and entertaining. The "hammer of dawn" gun is great. The cool camera view when running is a nice touch. However, the artistic style is very repetitive and the colors are very bland, so your brain goes a bit numb after playing for a while. Moreover, I'm personally not into the whole "I wear size 48 boots that weight 72lbs a piece but I don't wear a helmet" thing.
=== Story/Writing ===
Mostly crap. The story is extremely generic and completely secondary to the action. Some of the one-liners thrown out by your squad mates are amusing, but otherwise, there's not much to it.
=== Gameplay ===
This game brings a few cool ideas to the table, and for that I have to give it credit, but unfortunately, almost every single gameplay element gets boring in under 10 minutes. The cover system, for example, was unique for its time and is pretty neat... at first. Unfortunately, the controls aren't ideal - using the same button to duck, roll, sprint, etc will mess you up fairly often. Moreover, it's numbingly repetitive to just (1) duck (2) stand up (3) fire (4) repeat. The chainsaw is awesome initially, but it's exactly the same every time, so it loses its charm. The graphics are mind blowing at first, but the bland, over-used textures/colors bore you to death after a while. Having teammates is cool, but unless you're playing coop, you quickly find out they are pretty useless.
As an added gripe - and this is true of lots of shooters, including Halo 3 - most guns feel massively underpowered in this game. They sound like pee shooters (where is the "boom" of a gunshot?) and enemies can absorb an enormous amount of lead. When I complained about this, my friends said "well, it only takes several headshots".
Several headshots? You have to put multiple .50cal slugs through a brain to stop these guys? And to make things worse, the most powerful weapon in the game is the chainsaw. That's right, a meele weapon is a 1 hit kill to all but the toughest enemies. Bad guys will absorb 3 clips of ammo from my ultra-futuristic gun, but touch them with a friggin chainsaw, and they drop dead instantly. Lame.
=== Multiplayer ===
The one saving grace for this game, and the only reason to play more than just the demo, is the coop. You can play through the single player with a friend, providing cover, saving the other person if they go down, and so on. As with most things, it's much more fun with someone else.
Other than coop, I have not tried multiplayer, so I can't comment on that.
=== Conclusion ===
Overall, the game has some promise, but its fun is short lived. I enjoyed the game for about 30 minutes, after which I found it to be just a chore.
If there is a demo, try it out first. Play through it 4-5 times. This will give you a glimpse into what the game offers, but also show you its repetitive nature. If by the 5th play through you're not bored, then by all means drop $50 on it