Fun game.
Conversion ability is super necessary for Cowgirl player given their very limited magic resource. It'd be nice if Conversion was more automated. Something like click an ability you don't have the resources for and then the game calculates if you can convert to cover the gap and if so, present the player with a dialog where they can select to pay the gap with one of the other resources. No sliders necessary. No overpaying.
Also found a bug where if you buy the Generosity essence while on a level up screen, it will set your EXP to NaN.