This was great! I managed to beat the boss at the end (the sniper class is definitely very strong!). I really liked this. I love the class progression and it felt good to get stronger the deeper I went. Also it's cool to see another Love2D developer!
I also really like the tradeoff between digging more and killing enemies. On the one hand you can risk HP and fight enemies to get stronger, or you can just rush for the end (which is what I did once I got the sniper upgrade).
Great work!