Making sequels is probably pretty hard. I've never had to do it myself, but I can imagine. Especially when said game is pretty far into the franchise, and from a different developer. Probably one of the worst ways to handle this would be to essentially remake the last 'main' game in the franchise again. You've probably put together the pieces by now: That's exactly what Traveller's Tales did when they made Crash Bandicoot: The Wrath of Cortex.
I have a long history with Crash Bandicoot. When I was only 5 years old, my dad came home with a Sony Playstation. One of the games he had gotten for it was the original Crash Bandicoot. Our whole family loved that game, and we even got the sequels. I have fond memories of my mom with the strategy guide for Crash 3 reading from it to my father, who was playing the game. The kids sat and watched. Can you imagine that? The kids sat and watched our dad play through the game! We all got our turns, of course, me probably more than anyone. My favorite was Crash Bandicoot 2. My friend Kyle and I played that one the most, and Kyle was really good at finding all the secrets without any help. I was amazed when he showed me the secret warp room in Crash 2, and how to get there. Crash 2 remains my favorite.
Anyway, back to Wrath of Cortex.