1. There's more of a story this time around.
The Monster Hunter games have always been more about the experience than the story. Monster Hunter 4 Ultimate looks to try to make the story a little more than “here are some monsters. Hunt them.”
The player's custom hunter works for a traveling caravan that moves from camp to camp, assisting locals with what they do best: monster extermination. The caravan is also chasing after the Gore Magala, an unknown dragon creature that infects hunters and monsters alike with a mysterious toxic substance called the Frenzy Virus.
The virus works as both a plot device and a gameplay mechanic, afflicting hunters with debuffs and causing slain monsters to reanimate into more aggressive beings. Think of it as Monster Hunter’s own T-Virus.