Why is it that everything now has a sequel (or two), or a spinoff or something? Sure, it's been going on for probably 30 years, but a lot of times the sequel winds up forgotten.
Everyone remembers All In The Family, but how many people remember Archie Bunker's Place? Same for MASH. Some people remember Trapper John MD, which was a different style show with different actors, but not as many seem to remember AfterMASH, which featured some of the cast from the show in semi-continued timeline.
I brought up Archie Bunker's Place, and I'm sure everyone's thinking "Hey Giz, what about the Jeffersons? That was a spinoff of All In The Family, and it worked!" but that's where it starts to get interesting. The Jeffersons worked because it was characters who people liked, but had a minor role, going on to have a bigger role, in a different situation. And of course they had new minor roles to play off of theirs. That formula tends to work: look at Mork and Mindy, and Laverne and Shirley.
Joanie Loves Chachi probably failed because it was two main characters going somewhere else and being main characters again, only without any of the chemistry they'd already established between their minor characters, and of course everyone's drawing comparisons and keeping notes, so it's hard to get anyone to give you a chance.
God damnit, I knew I'd just wind up talking about Happy Days.
In essence, it seems like for a tv show sequel/spinoff to be succesful, it can't just be a continuation from the last episode, ie: "Tonight, after the touching conclusion to Friends, be sure to stay tuned for a SNEAK PEEK of our new sitcom JOEY!"
Second, it has to take a minor character, or at least part of an ensemble away from where we know them, and establish a new pecking order. Take Frasier, for instance. He was great on Cheers, but there was so much going on around him. Then, we get him alone, on his own radio show, with a father, a brother, a maid, a boss, and he doesn't hang around in the bar anymore. The focus is different, the humor is different, but with a character we sort of know. A great spinoff, just like The Jeffersons.
Thirdly, and in my mind most importantly, it seems like any attempts in the main program to set it up as a spinoff are usually the kiss of death. If Laverne and Shirley's part on Happy Days had been bigger, and they'd had an episode of "Goodbye Richie! We got jobs at the Brewery now, and can't go out with you and Potsie!", it would've weakened it somehow. We'd know what to expect, and know that somewhere there was still The Fonz and Howie around, and we'd sort of subconciously wonder how they would've played things out. Inevitably, L&S would've failed, and then they would've come back to Happy Days, just in time to put the kiss of death on their show too.
The only exception to that I can come up with is "Gomer Pyle, USMC", which had an episode where Andy took him to boot camp, and made sure he was all settled in. I'm sure there's a zillion I can't think of.
Movies, on the other hand, seem to do better when the sequel features familliar characters, in fairly familliar situations. On TV, you might have the sarcastic butler go on to be the Lieutenant Governor, but never in the movies. (Unless you were doing a sequel without any real continuity, like "Ernest Goes to Jail", or "Big Top Peewee". Great films, but hardly high drama)
(I spoil Rocky in the next paragraph. If you haven't seen it, tough.)
Also, where as viewers tend to forget a bad spinoff of a TV Show, a movie can be hurt by a bad sequel. As much as I hate to say it, Rocky 2,3,4 and 5 kind of cheapened the emotional impact of the original. Had Rocky been the only one made, and then a wave of nostalgia resulted in Rocky Balboa some 30 years later, with allusions made to the 4 sequels we never saw, it could've been a very powerful experience. But, instead, we'll always know everytime we see him go 15 rounds with Apollo Creed, that next time he'll do win. And that the time after that, he'll lose, and THEN win!
Every film maker now seems to want to make a saga, and admittedly, sequels seem to be making plenty of money. However, there's lots of times where a ho-hum sequel spoils things for the original movie. The Matrix was a good movie, especially with all of it's implied, but unwritten religious/philosophical themes. After Fyre and Rinku got done with the two sequels, and went ahead and confirmed most of the implications and went ahead with "Okay, Neo's Jesus now." it kind of spoils the subtlety of the original. It takes it from good science fiction with interesting undertones to the first of a three part beat you over the head with philosophy game.
There's been 3 Shrek movies, each one advertised as some kind of crucial "See it if you want to participate in polite society" event, and I haven't liked one of them. The story hasn't really gone anywhere great, and yet there's going to be 2 more! Same thing goes for Pirates of the Carribean. They weren't bad movies, but I never really felt such a great attachment to the characters that I thought I had to see anything beyond the first.
(SPECIAL BONUS RANT: There's a Shrek Holiday special! Add that to "Frosty 2!", "Rudolph 2" and a couple other celebrity filled reindeer and stocking type adventures. Why do they keep trying to make new "annual holiday classics" and sequels to the ones we already have? They're trying too hard to make these into something that'll last for 50 years, where as if they just make something fun to watch, it might last 50 years on it's own merit.)
The original three Star Wars movies were an excellent example of proper sequelage. If any one of them had been the only one to be released, it would've still been a good movie. The characters were interesting enough that you didn't mind seeing them again, they developed a bit as the story went along, and they were careful to keep the situations new and exciting.
The prequels were nowhere near as good, bordering on bad. But at least he waited around 20-30 years to put a bad taste in people's mouth.
Back To The Future was perfect, I don't need to explain why.
It seems with movies, the trick is to leave them wanting more. Almost all of the classic movies of all time didn't have sequels, and probably never will. You'll always wonder what the characters did next, and that wonder is why you can watch the movie a million times and never get tired of it. There's a lot of talk about making sequels to movies from the 70's and 80's, and I'm generally pretty skeptical of that. Rocky Balboa was great, and Rambo 4 looks incredible, but they can't possibly want to do anything else to Mad Max. You can't end his story better than it ended.
They want to make a sequel to The Goonies, but how the hell would that work? It'd just be a big circlejerk on the part of the actors, and I guess they've got the right to have fun like anyone else, but I think the resulting film would be a crime against the ticket buying public.
I might be wrong on this though, because I was worried about Indy 4, but the pictures of Harrison Ford in the costume are kind of selling me on the concept.
tl;dr Jesus, filmmakers! Quit trying to make an EPIC SAGA, and just make something that's fun to watch for an hour and a half. Then, if you still feel like you've got more to say on the subject, think before you throw the same title and characters at it.
(I spent two hours writing this crap. I'm a sad man.)
I guess what I'm trying to say is I'm going to make a game. It's not going to be a sequel, and it's not going to have a sequel, and at this point I really don't know much more than that.