I remember building a "vehicle" that was just a chair, some helium balloons, and a railgun. Managed to make it into whatever the lowest power bracket was. I couldn't move away from the spawn point (well, besides upwards)... and I could only realistically fire once every 30 seconds or so, due to the extreme recoil vs my ultralight balloon chair.

On the other hand, anyone who could fit wheels or hoverjets on their craft at this tier couldn't possibly be also using a railgun, so... I was nearly invulnerable up there, pressed up against the skybox, even if I could hardly hit anyone either. It was probably the worst build I made in the game, but thoroughly entertaining.

I will definitely never play this game again since they removed the flight-simulator-styled control scheme for planes. I'm pretty sure there were a lot of other changes that made this game less than what I remember it being, but it was pretty neat once.