The ability to heart an upgrade is nice, it communicates you want that upgrade. However, we only have the single button leaving some significant gaps in what we are trying to communicate. Do I prefer that upgrade or is that upgrade the missing piece that brings my whole build together?
In addition, I often see people hesitate on the purple upgrades. Sometimes one upgrade is clearly the good one, but maybe it isn't right for my build. I may not want that purple armor upgrade because I already have a great stone-skin engine.
Two more buttons could make a lot of difference. Limit the player to one option per upgrade and only one heart.
#Thumbs down
Communicating you don't want a particular