I too want to thank you for your detailed feedback.
Most people don't notice these small polishing issues. We had to cut down our initial polishing time from 3 days to 1-2 days. So we didn't have the time to fix these small issues.
Very interesting that you feel the game ends too early. My approach for making levels was to introduce one new interesting idea to each level, so there is always something new. I probably should have made more levels with smaller ideas that reuse many of the old ideas. And I probably should have done a decent ending.
It's still a game jam game, after all, but your feedback is really helpful.
Thanks for playing!
-Claas