Nicely done, my friend! I really like the sounds and effects, the animation was really good too! Everything well sync and balanced... Bravo!
Just a few points to work on though:
It`s really annoying trying to click on the units you want to (specially foes) when they gather up... But I really dont know how to solve that (maybe some zoom in function)
It would be nice if the upgrade tree showed the next level stats...
Nevertheless, great game!