You could get the impossible achievement from restarting a single level over and over due to its utter unfairness in design... unless you pay for special abilities of course. Stale gameplay with an unfair increment in amount of mobs and a random spawn pattern for every level as well, whilst you don't get any stronger in any way - in fact the amount of shots you have is inconsistent throughout the levels, at least give us more per level or something.
Honestly rather boring trying to get the hard badge. Every level is so similar and the same strategy of just bouncing balls directly into the wall works for almost every level I have done so far.
So far made it to level 67, there has been no need to guess in any of the levels, that much is true. It's a nice challenging spin on the classic Minesweeper, quite prefer this honestly.
 "Trifling Truffle Trouble"){kind=icon}
 "Mine of Sight"){kind=icon}
 "Overlord's New Mansion"){kind=icon}
 "Idle Tree"){kind=icon}
 "Three Goblets"){kind=icon}
 "Crusaders of the Lost Idols"){kind=icon}