Hey! Well done for a first Jam. I liked the overall game art a lot... it just got me into an atmosphere of relaxation in the menu and battle like feels or melancholy during the fight. Quite a lot of work for the cards characters. I found it a bit complicated to understand all the "rules" of the game but then just to decided to start and try.... lost the first round but then got an idea of how it works out best for me. However, I did not really get into all the details of the special abilities those characters have - there is surely a lot of more possibilities for strategy happening.
For ongoing development of the game I suggest to add multiple difficulty levels. The easiest way is probably to just give the opponent better chances for good fighters. While you could switch you would loose the already won rounds counter. Also I'd love more visuals on what is going on in the log... if someone is loosing health points or is blocking and so on... maybe put an overlay with that number there. And not just show the total result, but, after each log line you could just pause the game for a short time. So you get an idea of what things happen in what order. For example "disarm" (disarm highlighted -> symbol on target character added)... then Attack (attack symbol shown on attacker with strength) -> Defense (defense symbol shown, showing remaining points) ... and some sound effects for each action. Also it could be fun to give the characters funny names and maybe random personalized features (some scars or pimples, missing leg)... This helps the player to create a emotional binding to them and having a more intense good or bad feel seeing them survive or die.
Writing so much what could have been done: Your game is already very good. And given the time we had for the Jam, this is just awesome. And now its just easy adding more details to it, to increase the fun even more. It's those little details that make a game keeping the player playing and playing it on and on... and not just once or twice.
Keep it up! Curious to see any updates on this game! 👏