Ever since I joined the simpleplanes community there's a lot of things that i think will be great addition the the game if added such as.

-Cannon sounds ( the cannon sound is pretty lame, it's just a simple thud. So I think it will be a great addition to the game if the cannon sound change depending on the caliber chosen by the player.)
-Ammunition ( we should have the options to choose the ammunition. Like we can choose sabot or HESH and alot more)
-Lights ( this speaks for itself)
-Ricochets ( the "basic" ammunition always ricochet)