Im designing a coop 2d topdown game where the players need to clear waves of enemies in different maps by using weapons and traps (similar to orcs must die). I want normal weapons with limited ammo as a base (pistol, shotgun, smg, rifle) with turrets, decoys, mines and rolling boulders as traps. And some more ridicolous stuff as powerups (lasers, miniguns, bag ass bombs etc). Map awereness with picking up powerups/ammo will be important.
1. What about enemy theme? The enemies should be stupid AI-wise and easy to make graphically. They will enter at several points and travel towards an "exit", attacking the player if he/she gets to close. I want some variations, like some armoured guys, some quick etc.
Aliens? Zombies/mutants? What are they trying to reach that you must hinder? A portal? How does this work?
2. What would you think such a game needs to be fun? It's coop, two players at the same keyboard, no networking.
3. What coop-based stuff can you have in such a game? (beside reviving your pal:)
4. How would you earn resources/cash? By killing enemies? By combos? By collecting coins in the map?
Thanks for your input and opinions.