I've now played through the game, 100%ing it except for the Efficient achievement (reach the tournament in 20 matches) which seems pretty impossible on Hard.
It was a great game, so kudos for making it. Could well be/become a commercial title.
I have a whole bunch of additional feedback (incl. bug reports), but I can't copy & paste it here into the itch.io text editor because it's full of imgur links which I can't prevent from being turned into embedded images. Do you happen to have an email address or something where I could send the feedback instead?PS: Fair enough re: the X-cost card explosion thing. I do recommend making the game fail state more obvious, though, because players can't really distinguish between "this is a clever intentional fail state" and "this random web app just froze".