Really sick prototype. My only complaint is that when I tried to buy up all the red cards and make some decent combos, I actually felt weaker than just keeping my deck small. The issue with a bigger deck is that it's both harder to get useful combos in any one hand/turn, and it takes more points to upgrade everything (unless you want a turn where you just get a bunch of useless cards). Ideally, I'd like to tailor which cards to bring each trial a bit more.
Overall, though, I'm super excited to see what you do with this. I like deck builders (and incrementals, ofc) but it's a bit sad that every deck builder out there is a roguelike where constructing a truly nutty deck feels more RNG than fun.