Cool idea! I was stuck on level 1 for a long time before I read the comment on itch and learned that you could move horizontally, after which I was able to beat the game.
There were quite a few bugs/weird behavior that I encountered (you can die if you jump off the top, weird collision where you can stick to enemies and walls, etc.), but I think the core idea of an autoscroller that changes speeds depending on what you do is really interesting and definitely could be expanded into something really cool. Keep it up!