What about counterstrike source? The graphics aren't great but they are decent enough, and it has great "gameplay" if you can call it that since it's multiplayer. And Left 4 Dead is supposed to have great gameplay, and graphics look pretty nice too.
was it challenging at all? doesnt seem like it was since you are, of course, a superhuman that can slow down time to your liking and use overpowered weapons...
At some points its hard, but when you get a sniper rifle and you can slow down time (which i was using for 1/3 of the game) its just fun. But the ending just threw me off, i never expected alma to do what she did.