Repeat the formula, someone will complain.
Change the formula, someone will complain.
So, Marvel being Marvel, they did both.
Remember all the quippy one-liners and fast-paced action sequences? Yup, still all there.
Only, as would happen with a gang who've been together a while, they've grown up.
Well, most of them. Groot is is still a kid. But the rest of the film has a slightly more 'adult' feel.
No, not like that.
With Star Lord's past catching up with him and Gamora and Nebula facing their sisterly issues, the theme of family runs right through Vol 2.
And that's what really makes this film work.
We could have had all the same arguing and bickering while fighting the bad guy, but people change and grow and that's what the writers have managed to do here with the whole gang.
And to do that without losing any of the charm of the original is to be applauded.
And, most importantly, it's still fun.
While darker in tone in places, the one-liners will still make you laugh out loud and you'll still walk out grinning.
And, even more importantly, the music is still damn good.
And still as important.
You get nearly the whole of Mr Blue Sky at the start, you get two cracks at The Chain, My Sweet Lord will melt your heart - it's beautiful the way the songs are stitched into the story.
If there are any quibbles (and there usually are), it's possibly a tad long and the end credit sequences are now beyond a joke.
Where once you got clues to the next films on the horizon, now you get weak gags and too many of them.
Five, I think, but I may have lost count.
Either way, you'll miss nothing by ducking out early this time round.
But such issues are really minor.
Chris Pratt, Zoe Saldana, Karen Gillan, Dave Bautista and Bradley Cooper's voice are all still as you remember and as you want them to be.
Marvel have pretty much re-written the blockbuster rulebook over the last few years, with DC attempting to play catch-up in a whole new genre.
And yes, in some ways that's a shame as it squeezes out films that studios fear would not make the millions an action blockbuster with heroes could make.
But, when they produce something this fun and emotionally stirring, you can kind of forgive them.