Very nice! Good job on the self-explanatory nature.
Combining jump with jetpack is very satisfying. However, apart from that, the movement is a bit limited in my opinion -- the jump on its own is very weak (no way to economize fuel), the jetpack is not great for downward/horizontal movement, and it can be difficult to escape explosions in a direction other than up.
Minor bug: the game doesn't recognize when achieving the objectives out of order (e.g. buying the blaster before collecting 150 stones). The already-achieved objective then stays locked indefinitely.
Since the ore availability is random, it's possible that in an unlucky strike, one needs a long time (=fuel evaporated) + flies a lot (=fuel spent) + blasts a lot of rocks away (=fuel spent) until ores are found. Sometimes it's barely possible to break-even with the returned ores. Maybe it should be possible to use less efficient ways of movement (or mining), saving fuel, but as mentioned current jump is not that helpful underground. Possibly something like climbing/ropes/ladders/...
All in all, very cool mechanic with a lot of potential! :)