If I had to make a few suggestions:
Create some UI that clarifies the controls.
Make the enemies the same speed or slower than the attack animation, otherwise it is frustrating just hoping they don't dodge out of the way.
Maybe create some invincibility frames after getting hit once so that you don't get hit five times consecutively.
Slow the spawn rate for the holes (at least for the first level) and make it a bit more obvious on how to fill them if it takes multiple attempts or a certain amount of time or resources.
I know some games like to be difficult on purpose, but I found this just to be more frustrating than fun.