This is my kind of game! :))... I love this. The different skills, levels, minimalist art, etc. It's all great. Well done!
I actually made a game that looks and plays very similar to this one (but it's in a space/sci-fi setting), so I know this is a lot of work!
Feedback: Add keyboard shortcuts like 1, 2, 3 for the skills. Tab to switch to the next unit and dismiss the need to click to deselect a unit. These QoL improvements would enhance the game's flow a lot.