Well, this is definitely a candidate for jam winner - which is scary for me aha, i was starting to feel kinda confident until i saw this game.
These critiques are very unfair for a jam game, and mostly consist of me saying "more systems pls", but they might help you if you're aiming for a full release
- The game really needs to start smaller and grow - i was kinda overwhelmed on the first screen seeing 15 different cards for the first time lol. If you make this a roguelike (which it kinda felt like you were doing?) you should start the player with far fewer options.
- The between-level shop didnt seem very consequential, i think i used it twice. The game kinda already started me with a very balanced deck, so like, i didnt really wanna change much.
- Some enemies felt a little strange. I watched a regular archer guy just run away from the fight and had to chase em down, and i dont really know what the witches do? they just spawn passive eyes.
- Much of the tactical depth in these type of games come from party actions, but this is, obviously, a game about one main character which really limits the tactical depth you can reach. But i dont think that should change! i really like having one focal character. What i might suggest are summons! I'd suggest you make a totally different system for them - Dont make them cards, but perhaps let the player assign a subdeck of cards to each one. Theres so many possible ways you could go, but without them, i think you'll quite quickly cap out tactical depth.
- the "imp" card felt very weak. Yeah, vision is valuable, but the range is very short and it only lasts 1 turn. it didnt matter much.
I think you've got something really good here, but to reiterate: i do not think the design space of "fire emblem but you only have one guy" is viable for a full game. Your game plays like a mix of DND combat and slay the spire, a small party that provide support to the staff would significantly increase the amount of gameplay you're able to offer players at a relatively small cost to dev time.