After playing through the SP campaign, I must say I'm put off that they still use the infinitely respawning enemies trick again (even though I knew it was coming). It really breaks down the "suspension of disbelief" when you start to realize that the only way you'll clear an area is if you advance past a certain point to stop the respawning. Why couldn't they simply populate an area with enemies and allow you to advance once you've cleared them all?

The only thing that saves it from being a bust is that it is tough to detect in Rookie or Regular difficulties, since it's much easier to advance against the onslaught of enemies (only if you know that you *must* advance to clear the area). Once you try Hardened or Veteran, it becomes way too apparent because of how hard it is to advance. I actually started the game on Hardened, and was so put off that I went back and re-started the game on Regular and had a *much* better time. It wasn't that I was stuck, but that I was just getting impatient having to work against what I knew to be an infinite-respawn system.

I loved the storyline though, and thought it all tied together rather nicely for an action title. I enjoyed playing through the campaign a great deal on Regular, but I think I'll stick to Arcade Mode to try Hardened, because I can't see it as anything besides an arcade experience.

The multiplayer is unbelievably fun. I'm still getting a ton of enjoyment out of it.

I really hope they figure out another way of going about the campaign's "respawning" issue in 6.