Collecting and delivering mail has never been this dangerous. You're one of those funky US postal service workers who uses a plane to get the mail and then take it to it's destination. You must be somewhere in the wilderness, otherwise you would probably use a bicycle to deliver the mail instead.
Anyway, mail deliveries are not as simple as normal folk might think. You have to fly carefully to avoid obstacles, other aircraft, other anything to transport the letters safely. Set your path, set your timing and get that mail. Much easier said than done. Much easier crashed than delivered, especially during later levels in this game.
So, what we have here is a challenging timing-puzzler game Do you have the brains and the nerve to deliver the post? I hope so, this game is counting on you. Break a leg!