Great work on the combat logic and pretty weak in terms of theme.
The combat is absolutely solid, zero complaints there, the environment and characters look awesome, the main improvements would be to both readability and playability. Here's just some thoughts on my experience with the game.
Having keyboard controls is fine, but having the option to use the mouse for all actions would be amazing, the control bindings aren't very intuitive so I find myself having to keep checking the control scheme panel. Even if the bindings were more preferably I think I would still use the mouse over the keyboard.
It's not immediately obvious which character you're using or even if you're moving or attacking. In fact, the yellow highlight for damage and the red for movement is probably the opposite way round of what would be intuitive for differentiating the two.
The bar on the left has almost nothing to indicate its purpose, after testing, it seems it is both a turn order as well as the current and max hp of each unit, but there is no way to tell which box corresponds to which unit, even without icons having at least one colour for the playable characters and one for enemies would be a massive improvement, and then you can sorta intuit which enemies are damaged based on their max health and which have been in range the longest. For health indicators, this would probably just be most preferable above each unit or at least when hovered over, as even with individual icons, you would still have to program it so hovering or clicking the icon highlights the enemy it belongs to anyway.
It's of low importance, but being able to accidentally use a spell on a spot that won't hit any enemies doesn't serve the game at the moment, it's possible that later you planned to have ways to interact with the environment such as leaving either fire to block a path or some viscous liquid to slow enemies who try to pass through but at the moment it would be nicer without this feature.