This is a turn based game that plays like a real-time simulation. Excellent game concept. To really experience the full game you need to buy all of the campaigns (Pilots from different countries). There are significant differences in aircraft and the corresponding tactics. Even with this, the game is worth buying. I would have preferred to buy everything up front, but this approach allows you to see if you like the game before spending more.
I detest the IAP healing option for one dollar. Not needed and pure greed. The other IAP all expand the game; the total is a reasonable price for the game you get. Also, I hate the advertisements, even if they are infrequent. One star off for that crass commercialism.
The game has a few bugs that cause some mission crashes but they arent too frequent.
SkipperGlen about Sid Meier's Ace Patrol