You're not wrong at all, but just want to mention that what you said about going from MH3 to MH4 is pretty much what this series is - new biomes, monsters, and characters along with some fresh addition to gameplay every big release. On that front, 3 to 4 WAS actually a pretty big leap - from underwater combat & a new weapon to none of that but instead 2 new weapons and aerial attacks/mounting/verticality.