Actually Daisy_Dyme, that same logic can be applied to several other game series as well. Just to name a few, Mario, Sonic, Mega Man, Castlevania, Metroid, Kirby, Need for Speed, Halo, Half-Life, Call of Duty, Street Fighter, Guitar Hero, Rock Band, Tony Hawk, etc...
I could go on, but from the game series I listed, there really isn't much of any major difference between them yet they are still game series that people play and enjoy. If you break down any type of game, for example, a racing game, you'll see that its pretty much the same thing. Get from point A to point B and do so in 1st place. Even with this being the only objective, racing games are still fun and many people buy each sequel for different tracks, cars, and story. As long as people are having fun, they will continue to play that type of game.
I hope that clears some things up for you Daisy_Dyme
