When you play "Dead Island" you can immediately see what caused so many reviewers to complain about "choppy visuals" but it's still a great looking game that's fun to play.
"Space Marine" is polished from the very get go.
The introduction is epic, the music is epic and from the moment they thrust you into the midst of things the combat is epic.
I haven't seen melee combat flow so beautifully since "Batman: Arkham Asylum" and the gunplay is right up there with "HALO" or "Gears".
Haven't even tried the multiplayer yet but the customisation leves are supposed to be insane.