Some progress information: I've redone the gravity and rope swing code and improved the overall gameplay, it is a lot faster now. Superku has a new speedbooster, too, that can be activated by double tapping left/right. In ball mode, Superku can detonate himself to destroy breakable walls and to attack small enemies:
"Falls das Resultat nicht einfach nur dermassen gut aussieht, sollten Sie nochmal von vorn anfangen..." - Manual