Monster Hunter 4 Ultimate includes everything from MH4 but, you know, more. There are two new weapons classes (Insect Glaive and Charge Blade), new beasties, new sub-species, and plenty of new locations to explore. Underwater combat is gone (no one has shed a tear so far). Air combat is now a thing, but don't think you'll be flying around like a bnahabra. Instead, hunters have leaping vertical attacks to unleash, which includes latching onto monsters' backs and stabbing away. You know how launching players is generally considered a bad thing? Now you can launch them right onto monster's backs. It's tactical, dammit!