I liked the co-op as well, 5 was just so much fun. I think this should have co-op, but make it optional so people that don't like co-op can play alone and no one could complain about it because it's optional.
-MDK2 Wiiware, Megaman Legends 3 3ds, "manly tears" -Shenmue, Sonic 06, Viewtiful joe "have also made me cry manly tears of joy".
Think I'd prefer a solo RE game now. RE5 was pretty fun with co op but I'd like to have that fear where I'm by myself and there's no one else to back me up xD Besides I mainly enjoyed the co op in mercenaries since I use to play mercenaries constantly so Mercenaries 3D will give me that satisfaction.