Just played this and I enjoyed it! It's a bit tight and hard to navigate even with the map to be honest, the different wall textures/colors don't help all that much in orienteering until you're a ways into the game and know to recognize them.
I was glad for the no progress loss on death, as enemies are very punishing. The game essentially expects you to wait for them to walk near you so you can spam attack, otherwise if you walk to them they attack way too fast for you to win. Which either option is a bit of a pace-breaker.
Controls feel nice and tight, though I've had a few deaths due to QE being turn, a remap between AD and QE would have been welcome. But I admit that's more of a me issue.
I don't think the speed upgrade really helps much considering the mining speed is already quite fast, but it is funny to just instantly eat away at a wall so this isn't a complaint, just an observation.
That all out of the way, this was competently made! A worthy entry into the jam, you should feel proud :)