I really liked it, one of the most fun ideas in this jam. I'm sure programming this was a lot of effort, well done! With some expansion of content (enemies, cards, deckbuilding etc) I could easily see myself playing this game for a few hours.
Some suggestions:
I had some lag/timestop when I clicked on a card, not sure if this is intentional but it disrupted the flow of the game. Might be caused by me running the game in linux? Not sure.
Some cards which affect the player/enemy in some way that isn't +/- HP would add a lot I think. For example a card which makes you faster, or a card that slows down enemy bullets, etc.
Some type of border or line that clearly shows where you can move would help, dividing the screen into "card area" and "move area".