This game by Greenwood has a complete built-in cheat mode, which
 can be activated as follows:

 Start a level and press [F3] to [F10] one after the other, then
 type in the word CHEAT. Now a cheat menu appears. If you want to
 activate this menu again, it is enough to type in CHEAT.

 Now type

 [Shift] + [1]/[2]/[3]/[4] - Choose season