As txesmi noted, it's already the 10th anniversary of Superku, and to celebrate this I (re)post the original Superku game from 2002-2003:

Gameplay video and walkthrough: http://www.youtube.com/watch?v=EbYFYffh-h4
Download: http://www.superku.de/Superku_2003.exe

It's pretty buggy and contains some copyrighted music, but I encourage you to give it a try, have fun!

EDIT: Don't fly to high or you will die (Death Star logic). The level in the dark cave has a bright room, stay low or you will get stuck at the end. When you start the game, you will be asked to press a button with which you want to play the game (I suggest the spacebar, don't use S). Collect 4 Pelzkus in a level and you will unlock a new character, the 6th character is buggy and sadly cannot be used.