Really addictive. Nice and simple gameplay loop, good pacing, a very suitable game to have on a second monitor.

I think my only issue is the annoying tooltip showing immediately as I hover the map. i already understood the gameplay loop the first 10 minutes of playing, after that tooltips become unnecessary. I'd add a parameter to change how much time you have to hover the item to show. if I REALLY want to read it because I forgot what it does I'd just wait for like 3 or 5 seconds to show it, but showing it immediately becomes annoying.

Oh, and the achievement popup, I know there's an option to disable it. I don't want it disabled, but I'd like for it to be less invasive, just a "notification" with an option to close it or it would close in 5 seconds, non modal and without darkening everything.

Other than that, I loved it, super fun, addictive and satisfying. Well done!

Edit: Oh WOW! it has several maps with new mechanics? Changing the rating from 4 to 5.