I would like a Roadmaster level, in fact, it could be the train level too. I can see it now. 8 Heavy anti air cannons on the ground and its too dangerous for Arwings or the Cornerian Fleet to approach. Objective is to destroy their supply base, guarded by heavily armed train. Fox says Landmaster won't be able to keep up with the train, so Slippy offers to deploy the Roadmaster, and Fox agrees. You start most of the level off cruising through enemy ships and cannons, encountering most of the 8 anti air cannons along the way. Eventually you catch up to the train in the distance, some kind of chained mechanical flying beast bursts out of one of the 2nd to last car. Boss battle ensues right as the last 2 heavy anti air cannons come into sight. If you destroy all anti air cannons, Pepper gives you a transmission congratulating you on opening the skies then orders the fleet to lay waste to the entire base, train, and everything skipping the boss battle essentially. Mission Accomplished.

If you don't destroy them all, you fight the train boss as normal, when you defeat it the boss freaks out and tries to fly away, dragging the train at high speed into its own base and destroying them both, Mission Complete.