This is a shit ton of people for a jam, damn. Anyways, the feedback:
Visuals: The art is good, though the play space is missing some effects, a vignette is always a cheep an easy effect, just a gradient texture to fade out the edges and add a bit of depth, even with a faint one. A good idea would also be background panning, so there is a bit more movement during gameplay when you move the cursor, another part is that a common effect with card selection is to make them scale up when selected to mimic picking them up. Also the tweens could use different types of transitions, cause linear rising and falling feels a bit robotic. Oh also change the default theme of the sliders in the settings, it takes a minute and makes the whole thing feel a lot more polished.
Gameplay: I mean it is a bit easy, making the items kind of useless since you can easily win just because of the AI being kind of dumb. Also it would be nice to have even like an in game tab to check the rules, cause not everybody will check the description and the game kind of starts you off on a timer since you're not the first in the turn order.
Apart from that, the sound design is good, again the art assets are pretty, but needs a bit more life, and better opponents would be nice.