Regarding dig mode, I agreed. I made it because I had no time to add another visual for destroyable tiles. A bit overcomplicated, but less chance to get stuck.
Good concept, hard to stop digging even as a solo.
The only thing to mention is some trouble with the right spawner. Almost all the time I got a letter on the right and then again on the right. So no chance to keep rhythm.
The game is soooo cool. The difficulty curve is good, sometimes it is required very precisely calculating steps on the grid. Also, the music is relaxing and chill. Nice work!