I played this game through Onlive on the micro console. I can't compare graphics with any other version, as I don't own a xbox, ps3 or decent computer. If you are unfamiliar with Onlive, it is a cloud gaming service. The game is streamed to your computer or TV (if you have the little adapter which they are constantly giving away for free) from a remote server. Personally, I've had nothing but good experiences with the service, though I think it is primarily for people like me (too cheap/poor to buy a console or upgrade the computer as frequently as required). I pre-ordered the game. The good news for me/Onlive: because there was no multiplayer, Onlive gave me a $20 gift certificate, which I plan use to pre-order LOTR: War in the North (my cost will be $15 after the discount). The pre-order gives me a free game...so hello Deus Ex. Thanks Onlive, I've gotten 3 new releases for $60. Not bad.
The graphics on the game looked good to me.
As I said, the game did not launch with the multiplayer mode, and I think this was the case across all platforms.
The game starts without a typical training mission. At first I was wondering what to do...but it all came pretty naturally. As I moved forward though the initial area, I was given tips and weapon upgrades, until the end of the area..where I had a chain sword (woot!) and rifle. Ammo is VERY plentiful, with boxes of ammo (you also have an unlimited ammo pistol) and grenades strewn around so frequently, that accuracy isn't really an important strategy.
The game is (at least at these early stages) very linear. There was no map, but none required. You go forward. If you get turned around, an icon will show up pointing you in the right direction.
The combat is fun and simple. Lots of blood. You've got a gun in one hand and a melee weapon in the other. You don't have to switch, just hit an Ork with a chain sword and then shoot them in the face. You can also stun your opponents and then kill them with a fancy looking move (a lot like Darksiders), which also regenerates your health. Speaking of health, so far I haven't been too worried. There have been HORDES of Orks, but I've hacked/blasted my way through with only minimal damage. What damage I did get was easily mitigated by stun/kill moves. So far (and I've only played for an hour or so), the Space Marines are invincible engines of death and destruction (a good thing).
The story is...what you'd expect from a game called Warhammer 40K: Space Marine. There is an invasion on a strategically important planet. You and your crew need to get in and stop it. Speaking of your crew, you've got 2 Marines backing you up, but they are mostly cosmetic. They might kill 2 or 3 Orks to your 30 or 40.
Another nice thing is the lack of jumping. If they want you to jump, they'll give you a jetpack. When jumping time was over, the pack "got in the way" and had to be ditched. Personally, I liked this, the Marines look too bulky to be jumping around.
Overall, I had a blast last night playing the game. I'd like it if the multiplayer were available, but I'd also like to have the day off work so I can play all day..que sera sera. If you like 3rd person, Sci-Fi action games, copious amounts of blood and carnage or the 40k story...go for it.