Very nice
I liked your last one, and I love this one. Great fusion of low-quality 3D models and 2D animation.
A few things to improve upon:
-Higher framerate -- In scenes like the feet hitting the ground, you couldn't tell they were different people's feet because the framerate wasn't high enough to see the movement of the feet
-Like the last guy said, A pylon to power the cannons
-more variety of bad guys... maybe you'll add this later, but it seems like you're just using the basic units. It'd be really really cool to then have like a dark archon or normal archon or zerg lurker or something to be leading the attacks or something cool. I dunno.
Great job.