I came up with this list after seeing the relatively barren landscape of several games. While I was at it, I added some other items and thought of what a game just might need. I'm not screaming for any of the following, they are just various things for consideration. Some are needed, while others are just extras.
-- Detailed terrain: this includes river valleys, gorges, rolling hills, small creeks, large lakes and rivers, tree lines, jungles, streets, city squares.
-- Target rich environment: aside from strategic targets, which we currently have, there should be: small villages, towns, truck convoys, trains, ships, cargo flights, re-supply depots, forward HQ's, artillery fire-bases, pill-boxes, anti-tank traps, bridges etc...
-- Diverse aircraft: We don't really need more single-seat fighters, we need: close-support aircraft, bombers, attack planes, night fighters, cargo planes, anti-tank planes, dive bombers, torpedo planes etc...
-- Weapon options: this is deperately needed.
Currently we can change some options for armament. This includes impacts on how the aircraft handles. If coded correctly, you could allow for engine changes as well. If a given engine is mated up with a given weapons package the game itself could say "He wants a JU-87G". And assign various effects to the flight model. Only one downside: same paint job for every variant.
This is my short list. If you want a longer one, you'll have to wait about a week
Flakbait