This was really cool, the design were well done, the destruction was great, and just generally the game had a fun arcadey feel.
The only main issues I had was sometimes the game would get really laggy without any obvious reason why. Even more strange is the framerate improved when smashing a building, so there's definitely some optimizing to be done there. But ya know, jam issues.
I also think it would be good if there was a way to heal, maybe by eating some of the humans or something. Because I never really made it all that far without getting ground down by the tanks.
Also more of a subjective take, but I don't like the film grain effect, or motion blur. Disabling those or giving the option to disable them would be a good idea.
Overall though there's a lot to like about this, excellent work!