Battleground Europe started out mainly as an air sim that had the rest of the game built around it. In the air war you can do pretty much everything that actually happened. Strategic and tactical bombing (factories or infantry/tanks), strafing infantry or tanks, interception, dogfighting. Theres some people who make it through a whole campaign as top aces and never die but get loads of kills (usually with some fancy 200 dollar JS, but I got along just fine with an old logitek attack 3 with no z axis or hat). Theres also naval bombing elements as there are occasionally flotillas of destroyers or FMBs (little gunboats) and the occasional Transport with a few tanks. Only drawback is that you might need a subscription to fly any planes at all, or you MIGHT get access to a few lower tier planes that are available at the start of the campaign when technology is low (factories used to govern the speed that technology came in, but the Axis got really butthurt over this since there was an entire squadron dedicated to bombing their factories, leaving them with horrifically inadequate equipment, last I played factories controlled resupply).
Theres also more to the game. If you get bored with your plane you can play as an armored unit supporting infantry on the ground, or you can play as an ATG killing tanks, play as an AAG and shoot down aircraft, play as an infantry unit, play as a paraplane pilot and drop paratroopers, play as the captain of a Destroyer. Or if you get into it enough you can apply to join the High Command and realize the game is a bit of a grand strategy as well.
Oh also this game very realistically tracks armor amounts on enemy planes and vehicles, damage to individual parts and the ballistics of each and every projectile on the battlefield. Only health meter is on the squishy bits, the crew.