Wow, first of all, thank you very much for taking the time to write such a big comment. And yes, I wanted to do things well because this Micro Jam was my first jam and only my second game jam overall. That's why I reused a lot of little things from my other games, such as a script to make the bumping animations easier, the trail effect, the camera, the HTML auto-adjust, and that kind of stuff that usually consumes a lot of time. I also planned the game and some mechanics a few days before the jam started, so I was really happy when the prerequisite fit so well.
I also planned to have a finite number of waves, with a boss at the end and an ending, but I preferred to focus on other little details, and by the time I noticed, I was running out of time.
I'm glad you enjoyed my game! I love this kind of comment, and I'll definitely consider your feedback as well! :D