The game concept is alright. The first three zones have reasonable balancing for foes and bosses.
Not sure why the game asks you if you want to run the tutorial every time you start a new run.
Not sure if there's a way to tag Act 2 spoilers, and the emoticon isn't endearing but...
The Act 2 Zone 4 boss can resurrect the minions endlessly and regenerate its health to full... looks like the only way to beat a boss like that is to hope you get a godlike selection of abilities on level up, which is dubious game design.