Essentially just a few goobers and doodads and a few crappy guns, a cloud biome, a cloud island, and a cloud village. Also adds two ores being randomium, which can give you anything from the mod, and sillyum, being used to craft the two funky pets gooba and froggo. On top of that, there is a new hostile mob with a crappy model to go along with it, the joytaker. A few neutral mobs being the therizinosaurus and pan troglodytes (pan troglodytes has a class system! they follow the higher authority chimps!)
(btw the joytaker isn't supposed to be a garbage horror attempt like "oooohh spooky dweller!!!11!" bad models just aren't very joyful which is what he is supposed to be [not joyful])