Devs, just an FYI: The Sluice Box description is grammatically incorrect. Currently, it says Sluice Box is more sophisticated way to recover gold from water.
Sometime's delayed, but try my best. We also have discord, forums, tickets, etc that I have to monitor so it can be difficult when the comment-questions here are not as consistent =D
Stamina/Mana is an anti-bot system that was unfortunately required to be introduced into the game a while back, to prevent people using auto clickers from getting so much more progress than those playing legitimately. It doesn't actually kick in until a certain level, but once visible, it'll only decay when used outside of challenges. It will not be affected whatsoever in challenges, and there's usually enough to make your finger sore if you really want to click down a monster :) -Ray
You guys could add achievements that don't count towards the normal achieves, but so that they're just for fun, so it helps early players try and feel good. Might sound bad to others, but not for achievement hunters like myself.
@widgetdog This is the game that I truly played without getting bored and completed it, and I found 1-3 to be boring (I plan to do 3, though) and I don't think you are missing much.
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Heylo Isaac, Yes there is. Click SOCIAL -> Patch Notes :) -Ray