Overall an engaging card battler. After playing a few rounds and reading the instructions, I eventually got the hang of it.
It would be great to play a version of this game where you don't have to read the instructions to understand how to play. Imagine guiding the player through a series of easy battles, demonstrating how everything works, card by card.
Other similar games in this genre do a pretty good job of that. Hearthstone comes to mind.
This game was made during a game jam so there probably wouldn't have been time to do that sort of thing with the level of detail required for it to be effective. But it seems like the obvious next thing to do make this game better.
Some consistency of design would also help. You have to drag some cards onto an enemy to activate them, while others need to be double clicked to activate. Hearthstone lets you drag an "effect" card on to the battlefield to activate it, and having that option seems a little more consistent.
Allowing both the double click and the drag for effect cards makes sense, and then you don't need this extra yellow/white border design contrivance to try to communicate the difference. Cards "just work."
I didn't understand healing out of the gate. I think a stronger design involves cards which help you heal. That way the healing feels more like a strategic decision instead of something you get for not doing much.