Very fun, I love the screen shake and other visual effects (especially when running over enemies) and how much choice you're given as to who to deploy, what to make, what to focus on, etc.
If I could change one thing, it would be to have the enemies spawn from all one direction, and have that direction change over time, that way they still come in groups but overwhelm you less easily...
This is one of the games I'm going to enjoy playing for a while after the jam is over, hopefully trying out all the different strategies and options. I really hope you keep working on this, it's amazing so far!