This was my second game jam and first Godot game! It's surreal to see that people love the game I've created..
There wasn't much of a struggle, maybe because I've struggled much more on my first jam (GMTK) and previous games. It was all enjoyable to design levels and improve visuals, after I've build the prototype. The greatest learning that helped me this time is to create a minimum viable product, the basic platformer movement in my case, before working on art or other features. I've spent more than half the time just to perfect the core platformer mechanics, making it responsive and fun. That was the end of big challenges. Cool ideas come after that, and development is fast.
I've also learnt a lot playing others games; from how fast paced a game should be to making the game rewarding. On the whole a great experience!
(PS Thank you @DrManatee, happy to see my game on your favorites collection :D )