Idea would be to do the following:
For monsters:
-use WOB bots, that covers everything.
For levels:
-The obvious: build them
For leveling:
-This is a bit more complicated, it would go something like such:
-you get XP for each monster killed and each objective completed
-upon leveling, you get points to put into your skills(I would borrow GUI and system from my RPG)
-skills determine what weapons you have access to and how strong they are, as well as abilities(i.e building, painting, etc)
So an action-co-op game with rpg overtones.
