A rock solid concept which just needs a few adjustments to be really smooth.
Like people mentioned, being able to see where the evil rock is on the main screen would be nice. The shop's layout could also be refined to show everything on one screen instead of having a scroll bar.
Enjoyed this game and the feeling of gambling under pressure.
Also in my run, I think I got super lucky as with the jackpots, my rock took the entire screen only 1 minute in xd. Camera should zoom out so the screen doesn't get too overcrowded.