Thank you so much for the detailed feedback! Jumping Flash was a huge inspiration, so hearing that comparison really means a lot to me.
You're absolutely right about Level 2 — it ended up way too punishing compared to the first level, and I can see how it breaks the flow. One thing that wasn't clear at all: there's actually an elevator in the level that takes you back up to your last checkpoint, but it's nowhere near intuitive enough — most players don't even notice it. That's definitely on me. The boss fight also needs more variety so players can't just stand still and win. I'll revisit all of this before any future update. The idea of making Level 2 an unlockable is actually really smart!
Thanks again for hosting the jam and for taking the time to play through it!