+ New weapons, new enemies, etc. etc. etc.
- Needs cooperate play and more time to build base. There would be more time to build base, if friend would be killing enemies...
RockGod, you said this is easy, but you haven't got even 2 pro perfects? Get the impossible badge, and THEN say this is easy. And entombor, if the game is too hard, don't blame the game and give it 1/5. Please...?