With two very nice WW2 aircraft in the sim, have you considered introducing a standalone combat flight sim. I like the idea of the following two options:
1. A Pacific campaign with a scenery pack containing a few islands but mainly ocean (should reduce the memory requirements). Small airfields on each island with some belonging to the U.S. and some to Japan. Keep the corsair and lightning and add a fighter (wildcat or mustang), dive bomber and a medium bomber (B-25 Mitchell maybe). Add similar aircraft for the Japanese. The real challenge would be creating the AI or multiplayer mode and animating destruction i.e planes being shot down and bombs exploding. Gunship3d has proven this that this can be done well on mobile devices but add in your level of scenery, flight physics and cockpit details and you have the best on most popular mobile combat flight sim on the market which would attract a new customer base to your products.
2. A WW1 Northern France campaign with a map of the trenches. Keep the camel and add few other allied and axis aircraft such as neuports, fokkers and RACs. The good thing about this idea is that the aircraft are simple and although the scenery would need to be more detailed than in concept 1, the map could be small because of the low speed of the aircraft.
Just some food for thought!
Gary