Thanks for the feedback! I am currently working on an automated system to spawn enemies for the Steam demo, so this should help with the difficulty spikes, and it should feel like there is much more variety. On top of this, I am experimenting with giving the player full control of when mining happens / when enemies spawn.
For the movement, I have gotten many complaints about it and I am planning to rework it entirely at some point. If you have any ideas for what you would like to see when it comes to movement, I would love to hear them!