Well, the character-controll grew over time, so it wasn't that hard. Tho most difficult thing was to find the bugs in the huge code-mess at the end while debugging xD
Always a hard part for sure! In the last few hours, I added some levels and realized that in one of these new levels, a feature didn't work. I panicked a bit but I tried to move it just a little bit and it worked... I still don't know why it bugged XD