This reminds me of the old Lemmings game I used to play on Amiga (and was available elsewhere), but in reverse. I like the concept, though the controls and events don't seem quite where they need to be just yet. I enjoyed it and look forward to seeing it on Android (it is clearly designed to be a mobile game), where it'll make a really excellent way to pass the time. I hope the graphics get an upgrade for higher resolution displays (both my computer, and phone are 1080p, but this didn't even look 720p, maybe 320p). The style is great, would like to see it more clearly.
It could also be fun to have, in addition to maybe some event timers (think cooloff period), for each of the events (put a timer in each corner with an icon representing the event that direction causes), perhaps multiple crystals you need to protect in the more challenging levels. I could see trying to manage a cave with 4 or 5 crystals in different locations, and trying to keep the miners away from all of them could make for some really fast-paced gameplay if each event had its own short timer/cooloff period.