Wow! Probably the first jam game I've spent 20+ minutes in. I've really liked it, best clicker game I've played in a while. Also while playing I've collected some nitpicks/suggestions I would like to list:
1) Bomb bots stack up a lot of sounds in late game, which is very loud and annoying. Offsetting the sound pitch of a mined scale by a small random amount would probably fix that and make sounds more interesting
2) Drill bots feel underwhelming in comparassion to boom bots. Making them prioritize gem scales would make them more unique and not feel like they are a worse version of boom bots.
3) Making scale mining progress more visually obvious at first levels would make introduction more smooth
4) Same thing with the combo mechanic, since it doesn't have an audio-visual response it takes some time to realize it exists and even then the game doesn't really encourage you with anything besides a small text in the corner
5) Hold to dig upgrade or something like that would be extremely nice to conserve the fingers' health:)
6) It isn't always obvious where the cursor is pointing, which in conjutcion with small upgrade buttons make it hard to press them at first
Aside from that everything is 10/10 in my book, great progression, audio, visual and theming. Great job!