It's a common criticism that creativity in the game industry (or at least among the major companies) has become stymied because of the obsession with remakes and sequels. I agree with this to some extent, and it irks me when fans demand a sequel to a game that doesn't really need one for no other reason than that they really liked the game.
For me, the game that illustrates this tendency the best is The World Ends With You. I think it's possibly the best game Square Enix has ever made. I like it better than Chrono Trigger and any numbered Final Fantasy game. And yet I cannot join those who clamor for a sequel. I don't think that universe or its characters need to be revisited. The game said what it needed to say in one go, and a sequel would probably diminish the uniqueness and impact of the original. I wouldn't want it to become another franchise that's milked endlessly.
Now, I wouldn't mind if Square Enix took some lessons from what made The World Ends With You such a memorable experience. I wouldn't mind if they made more games with a modern setting, cool soundtrack, hyperstylized graphics, and a story that's offbeat and different without being bogged down by the pomposity and self-importance of the Final Fantasy series. But a direct sequel? Unnecessary and unwanted.
I've come to really appreciate Tim Schafer's "auteur" approach to game design. While all of Schafer's games have a distinctive touch that makes them feel like a Tim Schafer game and gives players some idea of what they can expect, he creates a unique universe with each title. He doesn't bother with Grim Fandango 2 or Psychonauts 2 (two more great games that don't require sequels), even though fans would probably be receptive to them. I wish more game designers and companies would adopt his philosophy.