The game is relaxing, but it's basically just two levels: find the color you can merge into one blob each turn, and find the color you can eliminate entirely each turn.
In general, lots of fortitude is your friend. If you're a mage, lots of focus to spam your powerful spells. If you can get the rogue book and then the dungeon sense talent, the last area will be a lot easier.
Trying to find hidden achievements (spoilers):
-Using Thief a lot in one game got me one
-A fence of over 150 blocks high got me one
-Having over 30 of each resource generator did not
-Having over 2000 of each resource did not
-Winning with curse did not, both by getting from 99 to 100 and from sending from 1 to 0.
-My deck is castle damage only, so I'm guessing that does not do anything
I'm not fully sure what happened here. I have two guys with level two machine guns and one guy running around at max level collection. Then I buy a guy for the last slot and give him the max level machine gun. Within a couple seconds the box gets a dead face and flies into the corner of the screen. I can still walk around and my collector dude is still walking, but the coins are stuck in place and I cannot access either store.