I GOT ALL ENDINGS!!! Here's How to achieve 'em:
1: Get crowned at school
2: Get hat from employee
3: Get moneybags from Mayor
4: Name a cat
5: (i think) STEAL moneybags from Mayor
Best: Find treasure in lake
Secret: Click on a raincloud in town hub, then go there. Bob gets nude and you get this ending.
The mystery upgrade turns the plane into the turtle from Toss The Turtle. This happens when your plane hits the ground, though. Finnish all upgrades, btw.
 "Learn to Fly Idle"){kind=icon}
 "Toss the Turtle"){kind=icon}
 "Pingy the Ping Idle RPG"){kind=icon}
 "Bob the button two!"){kind=icon}
 "Super Duck Punch!"){kind=icon}
 "Interactive Bob 2"){kind=icon}
 "Flight"){kind=icon}