Want platforms where multiple people can jump on and fly together. Also pushable load.
Sauerbraten can do that with elevators, but without steering.
Would allow rescue-missions, just looking around together, teamwork with one steering, one shooting, one jumps out at the wall and fetches something.
And easy to set up, build a mountain, place some guns, add a spawner for carpets.
Should act as playerstart, and eat loaded barrels for fuel

How hard would that be to code?
(sorry for english)
-Turblib