i pretty much echo what squirrelbaffler said. fantastic vibes! it's a strange game because i felt that the longer the round went, the easier it got. i got to wave 5 (i'm the second "megabrain" on the scoreboard but it didn't seem to save my name) and pretty much failed thrice in a row because i was off by one a couple times. selling cards makes it easier (though i agree with squirrel that sometimes it can make it harder by throwing your memorisation out of whack, but you have time to readjust and usually i have one card that i have difficulty remembering that i can just get rid of)
cool idea but i dont see it having legs past a game jam due to its simplicity. which, really, is a great thing! it means you scoped extremely well and you executed beautifully. great work