check out a game called Universal Combat
learning curve is like ^^^^^^^^^^^^ but its amazing and very in-depth
you can command a spacecraft, be a footsoldier, a ground vehicle operator, a in-atmosphere fighting aircraft, a space fighter aircraft, and some other stuff. spacecraft commanding is great, you can order entire fleets, and the in-depthness of the ship controls is awesome.
there are like 100 different things you can control, its pretty much everything Artemis is, but better and free. seriously, check it out its really fun. was made back in like 2001 i think. all realtime too.