There's a core of a fantastic game here! I love the twist on the PvZ formula used, and the graphics and audio are great! The concept of two sides of the moon fighting via turning the moon and plants is also really interesting.
However, like a lot of people mentioned, the difficulty is really unbalanced. Either you win the first round and you win them all, or you lose the first round and lose the game. The Dark Side's plant placement is completely random and not tied to an energy meter like yours are, so they could plant 5 shooters and destroy you or plant 3 stumps and rockets while you build up a good defense and crush them.
The best way to fix this would be to force both sides to play by the same rules, and making the AI a little less random, but I understand you didn't have time to do so!
Overall, the game is still pretty good, it just would be a lot better had it not been for the high difficulty! I'd love to see this expanded into a full game, with more tower types!