Coming from a Venturebeat interview...
“When we were localizing the game, we wanted to help out beginners more, as well as make the game easier to get into right from the beginning. We wanted to make the most intuitive Monster Hunter title that we could, so we reviewed the action portions and game progress, and planned more intuitive tutorials to help player progression.” - game director Kaname Fujioka
“I can’t give out hard numbers, but the amount of NPC dialogue is in the neighborhood of a typical Ace Attorney game, and more than Dragon’s Dogma [a role-playing game]. Then you have more text for things related to save data, online features, etc., and even more text related to non-retail releases like the eShop demos and instruction manuals. It’s easily the biggest game that Capcom has localized.” - localization director Andrew Alfonso
“… More than anything the addition of online play on the 3DS was huge. Obviously in Europe and North America it’s very difficult to play with others locally due to everyone being so spread out, so having online multiplayer in the game really showed the appeal of Monster Hunter’s multiplayer to a wide range of players.” - Kaname Fujioka
“First, I think the demo we released was a big factor. We got feedback from our overseas branches, and we made it easier to find monsters compared to previous games, and in general made it easier to play for beginners. Second, we had a lot of cooperation from our overseas marketing leads and our localization leads, who feverishly came up with idea after idea just for this title, and that was a huge reason why this game was as successful as it was.” - series producer Ryozo Tsujimoto