Very aware of the selection aura bug, it was one of the visual bugs I did run into. However this didn't happen in-engine, and seemed to only happen once exporting to HTML and running in-browser. So by the time I knew of it, it was too late to fix :/
The card graphic acts differently when you click it, this was intentionally left in, but it was actually a visual bug caused by a shader.
I'm guessing that cards not playing is likely due to them needing targets selected (or in some cases, you need to select both an enemy AND a friendly character), and this was likely made harder by the fact that you couldn't see what was selected properly, due to the visual bug.
Either way, thank you for playing!