a daily challenge with a leaderboard a la Slay the Spire with randomized run parameters would be so fun. that would become my subway crossword.
I guess it would have to be “unlockable” so as not to spoil any of the unlocked cards etc? that’s the only bit of friction I can think of - StS has “rare” cards but nothing the player needs to unlock.
I’ve only seen the meme mods on youtube where you can have all 150 jokers and break the game. I’ll have to look into one that tweaks the gameplay a bit.