As some people said before, more an idle game (if you don't do anything, you're still 3/4 effective) than skill required... just start and let it sink down, then upgrade. Mostly after you got the jump, better to idle and do other things :-P
The bomb damage is kind of ridiculous on the bosses... but I enjoyed this game a lot!
Also, there's a bug: when maxing out damage, you can still waste your upgrade point on your damage. Same probably for health
It is funny how the game assigns tasks. If three washing machines are broken down, one engineer fixes a machine and then goes to wait for the elevator, until engineer two comes in who fixes machine three. Hehe. Same for maids.
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