Very cool game.
First of all, I'll have you know, I beat the game first try without reading the tutorial. I'm mostly saying this because I'm quite proud, but I also think you deserve to know that you made one of your players proud. That's something to be proud of.
I really liked the flow of the game, the way your actions are delayed in a non, or at least, less frustrating way.
I like those ranges in which there are attacks which you need to dodge meaning there's a reason to retreat, and when I felt in the beginning that a lot of the runtime there was very little reason to not attack, later I started using a lot more techniques for optimal play. When at first I was like "why did they make this many different types of troops" later they all started to have their place and it made a lot more sense.
It would be cool if there was some way to push enemies back.
Although the music was very simple, it fit the style of the game very well, although I did sometimes lose what the first beat was. I think one instrument that plays one long fading note that resets every round would be nice, like a piano press that's being held down.
Second time playing through I sadly had much less fun, as I could not avoid the attacks of Colossos in any way, none of of the configurations worked. If the radius around him was a bit smaller I would probably have been able to retreat, but as is, he just hits everything meaning the only way is just attacking, maybe I just sucked, I guess I let him get to me too much, but what else am I supposed to do. The guardians also weren't very helpful and started going on their own adventure, even when I did defend.
The flanking unit and the mage enemy were my favorites.