I started the system of being in the air, with fully upgraded machine guns.
I came back later, and there were no monsters, no wave numbers, nothing at day 24. Awwhh yeahh.
Slightly dissapointed in the fact that if you buy every upgrade for the fuel, ramp height, or length, it has a much greater cost than saving up all the money and buying just the last upgrade
 "Best Friends Forever 3"){kind=icon}
 "Balloon in a Wasteland"){kind=icon}
 "Learn to Fly 2"){kind=icon}
 "The Idle RPG"){kind=icon}
 "Solipskier"){kind=icon}
 "Mr Runner"){kind=icon}
 "Smoking Kills"){kind=icon}
 "Storm the House 3"){kind=icon}
 "Take Your Canvas Bags To The Supermarket."){kind=icon}
 "Button murderer"){kind=icon}
 "Potion Panic"){kind=icon}
 "Wolf Games Apple Shooter"){kind=icon}
 "Gravit-Eye"){kind=icon}
 "Pixelist"){kind=tracking}
 "Planet Basher"){kind=icon}
 "UPGRADE COMPLETE!"){kind=icon}
 "Ether War"){kind=icon}
 "The Missile Game 3D HS"){kind=icon}