First of all, thanks for your feedback ;)
The controls are, indeed, a little broken, but the variable jump height was intended (we designed it as a “hold to jump higher” input), but ended up somewhat weird and buggy. About the lack of juice and feedback, we intended to make it clearer if you were progressing through the game and add a little more response to your gameplay, but the short time and a little bit of disorganization on our side hindered our attempts to implement such systems, so we ended up with more of a beta sort of thing than a full release.
Again, thanks for your feedback. Really pleased to know that you enjoyed the game.