Verdict: Fourth Shrek flick improves on previous outing to deliver a smart, funny finale.
The third Shrek sure did the business but it still felt like the big green guy was coming down with a case of threequelitis. It was both overcrowded with characters and underpowered with a storyline that no number of musical montages could disguise as being a thin redo of part two.
So adding another instalment risked lowering the bar even further.
After all, the third film had left him as a husband and father of three, his ogre tendencies having been tamed by the love of a good woman-ogre in Princess Fiona.
Which means this fourth outing is seemingly starting beyond the usual fairy tale horizon - what follows happily ever after?
Fortunately Shrek 4 comes up with a highly entertaining answer in a movie which is a vast improvement on its predecessor and which delivers a finale that echoes the heart and humour of the first.
It also makes effective use of being the first 3D Shrek. While it has plenty of sequences that dazzle with high-flying action or reach-out-and-touch texture, thankfully it doesn't feel that it's just playing to your recalibrated optic nerves.
Though if you hadn't been, like, born when the first Shrek came out in 2001, you might find some of it a little hard-going. Because, hey kids, it's a mid-life crisis movie.
Just as last year's animated wonder Up brought us mortality and grief and regret, Shrek Forever After ponders what happens when dads start wondering if fatherhood is all there is.
In Shrek's case, that means he's tired of his repetitive domesticity, his celebrity and that the local peasantry are no longer afraid of their resident ogre ("hey Shrek, will you sign my pitchfork?").
And while this Shrek gets a new fairy tale villain (Rumpelstiltskin), and has the usual allusions to pop culture past (Wizard of Oz witches by the score) and present, its smartest inspiration isn't an obvious one. It takes the premise of the 1946 Christmas classic It's a Wonderful Life and applies it here.
After getting done in a dodgy contract with Rumpelstiltskin, Shrek gets to see what would have happened if, like George Bailey in Wonderful Life, he didn't exist.
And it appears, nobody is better off without him.
That also allows the movie to have much fun with a topsy-turvy version of Shrek's world. There, no one knows who he is.
Having escaped from that tower by herself and bitter for it, Fiona has turned into a warrior queen leading a hoard of ogres. Puss In Boots is one fat furball. Donkey is just an ass. And angry wee Rumpelstiltskin rules the unhappy kingdom of Far Far Away, with the witches as his evil henchpersons.
Shrek only has a day before his non-existence becomes a reality, so he has his work cut out executing the loophole in his contract with the nasty wee fella, who certainly makes for the most memorable villain of the series.
All of which makes this a darker story than its forebears, which might not play so well with younger children. And some of the all-out action sequences feel like they don't know when to stop.
But it still has giggle-inducing gags, especially care of the comic sidekicks. Especially when that corpulent cat attempts something challenging, like moving.
With its adult concerns, it might be the most serious Shrek movie. But that doesn't stop it still being madly entertaining fun for the whole family - especially dads who might be convinced by this that buying that Harley isn't going to restore your inner ogre.
Cast: The voices of Mike Myers, Cameron Diaz, Antonio Banderas, Eddie Murphy
Rating: PG (Mild themes and animated violence)
Running time: 93 mins