Taken an idea from a SMW rom hack named "JUMP", I made a simple concept of how a "gourmet hindrance" style level could work in SuperTux.
The idea is as follows: you have to hit all the hidden blocks in the top wall before the egg falls into them (and at the end, you have to hit with exact timing). If you pass, you get an egg at the end that opens the way to the exit.
I found (not used in this level) that as a variation, one could also have one tile higher destroyable wooden blocks that one can break and thus clear the way by throwing up a rock from the bottom. I couldn't get this to become very playable though, so not included.