A decent game, however the upgrades are underpowered compared to how long the game goes, reaching level 20 by mostly clicking after a while with 23 pick, 26 speed and 15 click power, click power being the main thing that helped getting to the 20th ore. Since the game ends there all that really remains is making the cat able to pick it faster, but as a result the health and sword stats are pretty much pointless as the small stun from the mimick wouldn't add much to that, and the speed barely seems to actually effect the speed of mining at all that I can tell without having side by side gameplay to see a difference. So as a whole sadly the upgrades really don't do much for entertainment.
A big problem with upgrading both your clicks and the cats mining is that amount mined doesn't carry over after that specific ore, so for example if I mine 10/12 from an ore and then the cat mines 12/12 on the ore, it will only actually mine the 2/12 that remains of the first and not carry over, so this made farming gems and gold from lower level ores to get upgrades quicker actually sabotage the idle farming while clicking.
Problems aside it is calming sand I like the cat appeal. It seems like it could be better with some stuff added for sure, but not terrible by any stretch, just lacking in some rewarding feeling from upgrades.