Producing sequels to classic game video games is one helluva balancing act. If you deprive gamers of sequels, you risk irrelevancy (hello, EarthBound). If you flood the market with shoddy crap, you'll ruin the brand (hello, Sonic the Hedgehog).
That balancing act means even the most beloved gaming franchises have farted out a trainwreck of a game once or twice in their lives. The results range from simply unplayable to laughably insane.