Nice job! The controls feel quite smooth! I think that with some expansion/updates/polishing and some lore (as you already wrote in some comments) could be a nice platformer!
In the comments, you seem to appreciate critics/feedback and reporting bugs so (as I usually test games) I try to break your gameplay code and logic...I couldn't find almost anything strange. Only 3 small details:
- (I don't know if is intended, it seems too precise to be so) you can actually perform a kind of double jump (gaining only some extra height not doubling the height) with precise timing of double SPACE-BAR (not too fast, nor too slow)...although not easy to always replicate and use it
- I think is a bit strange that I can move the player before it touches the ground when he is re-spawning/spawning at the begging of the levels (especially if you are going backward)
- On my screen (on chrome with 100% of window scale, full screen or not) I was not able to see all the text of controls, At max (going as far as possible to the left) I see this:
Anyways nice work!