Just played the game, the first thing I want to mention is how amazing it looks, people often don't get impressed by pixel art but the way you use the banner behind the characters as a HUD element and you have knifes and bubbles and clouds moving, it works really well and it's fairly unique.
I feel even the simplest story would work with this game but it really needs one for progression, that and the ability to edit your deck is the only things I feel it's missing but it's understandable given it's a work in progress, playing with multiple characters for example you could run a only blue team could be fun but it's not necessary. And also did you tried putting the card queue thing in the left so it be parallel to the pillar? I think it would look cool idk.
PS Can't wait for the horses.