So, way I finally beat level 20.
Walkthrough shows this timing jumping and dodging bullets onto platform. Kept falling or had timing issue with strange lag and awkward button combo. So instead I threw head and jumped back to the left, landing on top of the pumpkin. From there, take pumpkin head on and hit switch to bring platform back over to the right. Get on, hop up to use switch and ditch pumpkin by throwing to right. Now you have time to jump to the left without worrying about if the platform will be low enough in the exact moment you need.
Sure, go for the easy badge they said...
Didn't tell us that every player in there has lasers or powerful guns that make your pea shooter absolutely worthless...
So found the reason why I couldn't win.
The game seems to have a mechanic requiring you to physically break through each door. If you get the hang glider, it's possible to overshoot the first door, and thereby, impossible to beat the game.
Is that something that could be fixed? Seems kind of unfair to do that.