Great game.
I really like your card/queue system, after having to get used to cards taking mana immediately the game became smooth. A couple of times I accidentally killed deacon by not paying attention to the mana, so having a warning would be nice.
The rouge-like concept is great until it screws you over. My first run I had nor rest and always ran out of mana. The second try was better, except I think I took too many red cards. Still I managed to beat the last boss after several attempts. There are some cards where I am not sure if they work, for example there is signature move that supposedly deals 2 dmg + 2 more if it is the only red card in the queue and is undodgeable. Maybe I can't have a red card in either deacon or princesses queue but it never seems to hit when the enemy evades.
Then there are times when the enemy does only red. It's pretty much unsurvivable. But I guess that is just how rougelikes are.
All in all, great game, keep it up.