Once upon a time, in some prairie far away, there lived a herd of "varmints", raccoon-like creatures, who lived in harmony with nature (albeit it was just grass and sparse trees, from my point of view). However, one day, the land is transformed forever as other varmints (burlier than the first ones) pull up darkly colored buildings on the plain, which turns the surrounding land dark and unlivable. One varmint, however, saves a branch from a dying tree and tries to keep it alive. The tree eventually seeds, giving birth to surreal jellyfish-like havens which evacuate varmints from the now-dying city.
I think the film is very properly named, considering that the word "varmint" means "an irritating or obnoxious person or animal". The true varmints in this story are, therefore, the ones who pulled up the dark buildings, but are only (ob)noxious to themselves; this I find to be ironic. One other thing that I would like to point out is a difference between the free-roaming varmints and the city varmints. We can clearly see that all the varmints in the countryside have free will and a sense of self, while those in the city fail to show any emotion, instead acting as a mindless team.
A few flaws I would like to point out: first of all, there was running water in the apartment (the protagonist washed his face with it) but why does he even bother trying to collect it on the roof if so? Wouldn't rainwater be more harmful, considering that the city pollutes everything it touches for no real reason? I hate the exaggerated message in this film as well and the way it's shoved into us. WHY did the city varmints decide to build darkly-colored, ominous buildings for no other reason than to advance the plot? Why did we need a bland, cliché love interest when we didn't need one? Although I'm alright with the idea that we need to save the environment, I don't think this film qualifies as an effective vessel for it. The animation was great, though.