I liked the game. It had a good premise and gameplay. However, it seemed a little too easy. I played through the first two levels two or three times and got a lot of levels. I maxed out my weapons first, and with that, I was able to rush through all 15 levels. On the second playthrough, I just maxed all difficulties and was able to beat every stage easily. To make the game harder, I think you can nerf the upgrades, because your plants end up being stronger than the enemies. Maybe the nerf could be in a hard mode, since you'd then have to swarm crystals, sell plants, and maintain strong plants in the back.
Overall, it was fun!
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