Game development has always been a sequel-friendly environment. More often than not, developers release sequels that build upon and refine their existing formula, and as long as it's done well, I've got no problem with it. I am, however, a little nostalgic for how a couple developers treated sequels in the mid-80's. While most sequels still focused on incremental changes, a few went in wildly different directions, the most famous being the US version of Super Mario Bros 2, Castlevania 2: Simon's Quest, and Zelda II: The Adventure of Link. The third installments of each of these games would undo these changes, but to this day I think Mario 2 and Zelda 2 are among the finest titles released on the NES. I hold much less fondness for Castlevania 2, but still respect it a great deal.
