My son and I thought of some fun ideas for levels. 
Moon Bases- two teams each have a moon base. The object is to go out of the airlock and raise your teams flag before the other team. If you stay outside too long you will run out of air and "die". With lower Gravity, if you get hit with a spinning weapon, you fly off the moon.
Oasis- Basically the oppose of the campfire level. There are 3 oasis pools that the sun is slowly drying up. If you go too far from the water, you will pass out.
Safari Ride. A Safari truck
truck goes around in a circle, players will need to try and stay on top while it is moving for a certain about of time.