Good first attempt at a turn-based strategy game! Also really like hypnotizing mechanics in any game, so already went into this with a good impression.
Some small improvements that I think you can make, I noticed that even when hypnotizing an enemy, they'll still take their turn anyway afterwards. I think consuming their turn by hypnotizing them could add more strategic debt to your game. Also, some potential UI improvements include keeping buttons at generally the same place. For example, the fact that the okay button shifts sometimes when there is more text makes it harder for me as I keep having to move my mouse. In addition, I have misclicked heal so many times when I actually intended to click attack because attack is usually the first button.
Some larger improvements to consider if you intend to improve this game, or for future games, it is generally always better to keep mouse movement to a minimum to make things easier to navigate to. e.g. if you want to keep mouse clicking to selecting targets, tying the selection of actions to keyboard buttons instead (e.g. 1 to attack, 2 to do nothing) could make the gameplay more streamlined.
As for bigger gameplay changes, I understand that this is a game jam entry, so content-wise you would be very limited due to time, but having more unique enemies, with differently acting moves would make the whole hypnotizing mechanic much more enticing. The healing enemy is a good example of this, and others could include enemies with AOE effects, buffs, debuffs, etc. That way, the choice of who to hypnotize again adds more strategic debt. I also find the choice to do nothing a bit useless currently, I cannot think of any scenario where I would do nothing for the current state of the game. An interesting way to incorporate it if you really want to keep doing nothing, which honestly could be an interesting choice, could be e.g. a bomb enemy that explodes within a certain number of turns, and doing nothing restores more turns to when it will explode.
All in all, the fact that you got me thinking of so many potential things for your game definitely shows that you are onto something here with what you currently have, at least in my opinion.