In the current game play, agree with earlier poster in saying the G-copter would be over powering. Some ideas to tune the power of the GC:
1. Make the GC fragile.
2. Make the GC hard to fly. Tougher then shown in video. The copter should have stalled and fallen to ground when the steep angle of attack caused forward airspeed to stop.
2. Introduce zombie bats to the game that only come out at night. The bats only attack other things that fly, making flying GC at night suicidal.
3. Make the gas tank very limited or gas consumption high, say 50% of the mini-bike range on a single tank.
4. No extra storage, only the player backpack.