Whew, I'm shaking. I found it frustrating and hard to control, even once I figured out the mechanic. At least I think I figured it out, I was unable to consistently drill upward, jumping and then drilling down seemed to work the most reliably. In the areas after you get the dash there's many places that require very precise timing. I wouldn't have even gotten as far as I did if the game hadn't taken pity on me and occasionally moved the checkpoint past spikes after I died just on the edge. That second room you showed here is where I gave up.
This is a cool idea, there's something really freeing about being able to tunnel straight through, it's almost like swimming, and well developed for a weeklong project. Thanks for submitting it!