A very solid gameplay foundation to build upon, lovely concept and style. Clicking things was satisfying. After a while both enemies and rocks started spawning "in the air", just a heads up. This screams for some story and clearer direction for the player in the future.
Suggestions:
Increased enemy variety.
Craftable power-ups which increase speed and rate of gathering.
Maybe being able to craft some visual details, alternative costumes and the like.
More things to do in the room, perhaps additional details which tells you something about a potential story.
A couple of characters to interact with, just some basic dialog brings a lot of value.