I made a bunch of quadrotor drones lol, some of them transformed, some of them had counter rotating rotors on top of each other, used variable pitch to determine lift power, some of them were controlled using shifting weight blocks and some using torque reaction wheels, they were all beautiful but I used none of them to complete any levels lol
flight isn't hard but it is hard to make a flying machine that also looks good, the only thing I built to compete a level was a sniper platform that floated using a lot of balloons, it was difficult to use since the gun was heavy and the torque of the mount affected the platform
also had a few tanks using treads that would drop my fps to like 20 lol, a few of them transformed too, they were bigger than the boundary box in full extension with the tension needed for the treads, knowing me I've probably posted some videos of some of the stuff I've made before
/tism