Thanks for the feedback. Definitely still working on this idea, and a lot of it was rushed for the Jam. We've since had a bunch of ideas on how we can improve the system which we'll try out.
This was mostly an experiment to see if real time combat + card deck building is a viable combination.
Check out "Slay the Spire" for a great turn based combat deckbuilder!
You can play with mouse for selecting cards by the way, though I prefer to play with Arrow keys + Z,X,C,V personally.
WASD and Z,X,C,V would be terrible, you can use H,J,K,L instead.