Really ambitious entry!! And very very fun! I mostly went with overwhelming the enemy with the cheapest unit and praying that they don't die all at once.
Obviously the only major complaint would be that your units don't avoid obstacles, but that wasn't totally bad, it actually added a micro management element that made it more interesting!
I managed to beat the last stand (actually there was a building still standing, but the victory screen appeared) then the last stand begun again, was that supposed to happen? I still considered that as a win! :).
The sound was great, and the music gave it an awesome atmosphere.
Great game and surprisingly solid execution considering the complexity and the time frame!