User blog comment:Mckrongs/Monster Hunter 4 for the Nintendo 3DS/@comment-184.38.31.23-20121125034327/@comment-4212769-20121125051435

There is a big difference between 2nd gen and 4th gen.

While 2nd gen was more or less just an expansion of 1st gen simply taking over all monsters 4th gen again made a new generation only using some monsters from different generations and put them together to create a more "MH-Allstars" feeling with new monsters.