It's basically this show about a retarded (I kid you not, it's pretty damn obvious) old man who is somehow magically everyone in the world's Uncle AND Grandpa. I'd get a restraining order if I knew that guy. It's one of those shows that makes fun of farts, fat people, teenagers, acne, etc. The stupid things. In what I saw, they make a fat teenager with a face of the loveliest acne (source of the above) freak out over Uncle Grandpa falling through the ceiling and smashing is computer. Then UG says he will build him a super computer, and the kid begins to sweat and they visibly make his nipples sweat through his shirt. It's just gross.
Honestly, I can't find one good thing about this show. The animation is horrible, Uncle Grandpa is completely and utterly one of the worst characters I've ever seen. It's another creepy show like The Misadventures of Flapjack and the Problem Solverz. Disturbing. There wasn't anything Flapjack level disturbing in what I've seen of Uncle Grandpa, but I imagine there will be in the future.
I enjoy a little bit of immature humor myself, but this is not the right way to do it. "Oh, look, he can fly with his farts! That's so funny! " Said no one. I can't imagine anyone liking this. I can only hope that it gets cancled after one season. But it always seems like the horrible shows keep going and the rare good ones end.