I agree, Nintendo's series have the same main characters all the time but lately, they have been good at including new additions (Midna, Wolf Link, Rosalina)
Pretty same/similar world?
So a castle is pretty much the same as a galaxy? Or an tropical island?
And Wind Waker, is that gone? Really, TP is the same place all over again, and even that was slightly changed, but let's not get into that, I agree, it is pretty much the same.
I haven't played Metroid 1/2, but I believe 3 was set in a fairly different place.
Also, I think some people like being the same guy all over again. I feel kind of sad when I know that the game is over, person (insert name) is gone.
http://www.vgchartz.com/games/userreviewdisp.php?id=261
That is VGChartz LONGEST review. And it's NOT Cute Kitten DS