At the very, very end of the test there was a nasty bug in the mines. I believe Rascalmom did an in-game bug report... and I know she snagged some video.
At one point, sometimes on the first action after a reload, sometimes several mining attempts later, the action would get 'caught'. The sound would continue going (like the Street Project 'Work' bug) and the action appears to complete... but you get no reward. You can then start the action again (with no visible progress to the rock), adding a second audio loop to the mix. The action completes, gives the correct energy/xp fixes but no reward (no rocks). I got 6 cycles of this going before my nerves had enough.
Changing streets had no effect... you could mine a different rock with the multiplied audio still going... I left one street with 3 'tinks' and that grew to 6 with a different rock on a different street. Only a refresh stopped the noise. Only leaving the mines stopped the bug.