This is smooth. The physics are fun.

I love the idea of similarily controlling some units with different skills. I have a similar idea for my game for future devlopment.

I failed to defeat the red guys, but I really enjoyed playing. It just gets a little slow when both troups don't have many guys left. Maybe you could implement a sudden-death-mechanic to speed things up when troup-sizes shrink on both sides?
I really hope this will be a true fighting system in one of your future games!

Did you implement audio though? I didn't hear music. Trying to figure out if this is a bug. Would be a shame to give you a bad rating there, because the game is fun