Hurrah for them, I thought, doesn't mean it's actually any good...
But the trailer had contained a couple of chuckles, and although it didn't look like it was going to change the world it promised to be an entertaining way to kill 90 minutes.
Sadly it was the promise that was killed. The 90 minutes just dragged.
The story is a simple one - Hiro has lost both parents and is living with his brother Tadashi and their aunt at her cafe in Sanfransokyo (no, me neither).
In a bid to stop the child genius from wasting his time in robot fights, Tadashi takes Hiro to his lab where he discovers science and stuff (because apparently he didn't actually know what his brother did all day).
One thing leads to another, tragedy ensues, lots of people run around, friendships are made, things blow up and several other films are ripped off (or referenced, depending on your point of view).
At the centre of all this is Baymax - the big white puffball you'll have seen on the posters.
Invented by Tadashi as a medical assistant, Baymax is very much the star of the film.
Cute, odd-looking, funny - he's the stuff marketing men dream off and children will love. Which makes you wonder why they take so long to introduce him.
And that's just one of the problems with this film.
Baymax is the heart of the movie, something that is highlighted when he's not on the screen. He provides the warmth and the laughs.
And this film needs laughs.
From the outset (the opening 20 minutes are basically Up) we are told Hiro has lost both his parents, so death is thrown up there nice and early. Which is handy, as it's a recurring theme.
It's as if the makers looked at Bambi and went "pft, they only kill the mum..."
Sadly, death and destruction far outweigh the laughs. To the extent that at least one child was reduced to tears in the final third.
Which would be fine if this wasn't so clearly a children's film.
But the tone isn't even the worst of Big Hero 6's problems.
As well as ripping off Up, Contact and Stargate are thrown in the mix, along with a large slice of Iron Man 3, a cheeky Superman reference and a nod towards The Avengers.
Or G-Force. They couldn't really decide.
Oh, and Gravity. That's in there too.
Somewhere in the development process of this film, someone took the idea of a boy and his brother's robot and got chatting to a bloke in marketing.
And that's where it all went wrong.
What you get is a ton of different films, a super-hero group that aren't named 'til the end (once you've seen this you'll see why that's a problem) and a mashing-up of Japanese and American cultures which does neither any favours.
And then someone else said 'let's do it in 3D'.
So on top of everything else, you get at least three scenes that add nothing to the film but look pretty with the glasses on - but sadly bore the kids, if the shuffling around me was anything to go by.
Apart from all that, though, it's not bad.
I did genuinely laugh at least three times, and when I wasn't spotting film references (even Bullitt gets thrown in) it was quite enjoyable.
If you don't mind all the stuff about death and people dying that is.
Oh, before I forget, this film comes with a short film about a man and a woman and their relationship as told through the eyes of the man's dog.
If you ignore the issue of just taking dogs off the street without first checking if they've actually got an owner, and don't focus too much on all the things you really should never feed a dog, it's quite sweet.
Granted, it does feature a dog welfare message at the end, but blink and you'll miss it. Still, at least it didn't make anyone cry.