At first the tutorial text scared me a little because there was a lot to remember. But after the game starts you get the gist of it really quickly
It is very hard to make a balanced game that includes randomness, and I think you did a really good job on making it fair and enjoyable (even though I got multiple times into situation where both me and the enemy had low attack and high defense, and we were just missing each other for 5 minutes until someone got lucky to land a hit :D).
Really like the permanent upgrades mechanic that adds sense of progression and "becoming stronger" feeling.
Anyways, game is fun, presented well and very enjoyable. Hope you find a good way to make it more balanced after the jam :)