Pixel shaders, but not overdone like 90% of games out there.
No vulgar lego effects from bump/normal maps, no ultra shiny or bright stuff like people are doing with skin materials now (e.g. that fluorescent 109K skin), just the right amount so it looks real. Reflectivity map so we can make paint chips or bare metal areas on skins, that glitter just right.
Sparks, contrails, gradual oil leak texture, a minimum amount of reflection from water, Jet engine flame sprites with just the right wavelength and size of heat dilation..
-Historical tracer colors, or a choice from them, if that doesn't offend anyone's sense of historical accuracy.
-Exhaust smoke when engines are firewalled.
-CM option for no icons forced.. Or a range of options like in Il2: exact visibility distance, fade in/out variables, or maybe a scheme like in WWIIOL where icons will fade out if you don't look at them for long enough.
-Smoke for the Tiger and PT boat
-Obscured cockpit vision when single engined fighters get their engine set alight.
-Skins in missions, forced or free, ignored on any front end that has them disabled.
-Impacts visible on GVs, scrapes or charred paint
-Tinted reticules for the planes that had them.
...
-Tank turret rotation control from driver's seat, or buttons to remote tank turret to turn to cardinal positions.
-Independent track control on tanks that had it
-A way to set separate salvo values
-A button to salvo everything.
-A button to lock/unlock the clipboard map's zoom and/or pan.
-Troops and cargo added to the damage list.
-Leading edge slats added to the damage list.
-Quicker damage to the pilot when on fire
