This mechanic definitely had me scratching my head. If it somehow allows you to change decks or has more enemies, I will definitely be up all night playing this game!
About this version.
I completed the game on my first playthrough without taking a single damage, so I was fine with a more challenging difficulty level.
Basically, a simple strategy worked for me: resupply as needed, and whenever you can attack, prioritize and keep shooting until you take them down. I think this can be solved with more enemies and more cards.
Anyway, I'm pretty excited about this game, and I'm looking forward to playing it again. Thanks!