As it stands I heavily advise AGAINST buying this game for several reasons.
1 - You can lose all of the pilots in a squadron simply because they're too terminally stupid to make the decision to bail out themselves and it's often an impossible task to hit the bail out button the game gives you in the *tiny* window of time available to you to do so while the pilot's plane is under fire.
2 - Withdrawing is not an option, say your pilots have stripped away the fighter cover for a flight of bombers but are in no shape to carry on the fight? Tough. It's very much the stalinist approach of victory or death, if you go back to the map you're left at the tender mercies of the auto-resolve system (which will happily let four bombers wipe out a squadron) or you're forced to fight on and risk losing all of your pilots to problem #1. (Yeah having to tell your guys to bail out is irritating.)
3 - No big wings. The 'big wing' was a tactic in which several RAF squadrons would group together to engage enemy attacks together, it took time to set up but it helped even out the numbers against massive German formations. This game does not let you do that and instead expects you to fight off dozens of planes with just eight of your own which leaves you at the mercy of problem #2 wherein you cannot withdraw should carrying on the fight become foolish which is particularly infuriating if you have another squadron or two nearby that could take over.
4 - The voiceacting is terrible, I had to turn off the audio for the tutorial guy just because I couldn't stand the sound of the mans voice.
5 - If you accidentally create a squadron at your airfield when that airfields squadron is in the air, tough luck. Doesn't matter that this new ghost squadron has no planes, you can't delete it, move it or do anything with it and you now have as many as eight rather expensive flying machines in the air that can't land because the airfield 'is full'. Despite the ghost squadron again, having no planes.
If you have your heart set on this game wait a few weeks or even a month or two for some patches to come in, otherwise you're setting yourself up for an absolute pain in the rear.