Good start, needs content and balance.
This is looking like a very fun game engine. I really like it, because it has a lot of potential. It is pretty fun to play, and fool around with.
However, my problem #1 is: too little content. There are just 5 levels, which is just too little. I would really like some sort of world map with regions (which are levels) which I have to conquer one after one, choosing what civilizations to attak, which territories to take. Maybe you could even add some sort of permanent upgrade system based on points you get for conquering regions, and special bonuses (like.. unlocking factories!) for conquering the right territories. This would fit the story and make the game fun for a longer time.
My problem #2 is balancing. Zerging is _far_ too strong. I just beat every level by just cramming as many small pyramids into the place (maybe adding some dark huts to get some roads below the main road), upgrading production rate and after that upgrading random things (usually, range first for more damage because more bots can shoot). After that, the enemy just gets overwhelmed. Even EMP cannot save them in that case, because ALL bots die and I produce more bots faster than he does. I think this results from the lack of area of effect damage to counter such large numbers of stuff and from too little benefit from the better bots. In fact, most larger bots are just bigger smaller bots (like, the tank is just a large shooty robot, while the mummy is just a small shooty bot, but those 5 mummies I can produce for 1 tank kill the tank thanks to overkill and too little fire rate of the tank), so overall having more smaller bots just offsets the statistics advantage of the larger bots. I'd like to see something like starcrafts psistorm added, or suicide bombing robots which can take out hordes of smaller weaker robots efficiently, but suck against bigger robots with more health.
So, overall I am going to vote for some 7/10. It is no clear 10, because it feels mostly like an engine demo due to length and balance, but it is fun and has potential.
However, I'm looking forward for a second version of this game and if it comes, I'd volunteer as some sort of beta-tester, I guess :)