So what do you think, was Donald just trying to get Sora to cheer up by saying 'this ship runs on happy faces', or was he actually serious?

 

Cause the thought of Sora, Donald and Goofy in wide smiles while navigating through obstacles and blasting heartless ships before they hit them seems a bit unlikely.

 

Any thoughts?

yup.....he was cheering him up...in kh2 sora wasnt happy in the ship one time(its not a cutsecene but those secenes that they talk with sound and the talk appear on thier heads)sora was pretty sad there..

well yeah he was cause if you remember, the reading for the World That Never Was got stronger every time they helped people...

There's also a scene in the KH manga where they are all smiling as wide as they can in the Gummi ship, but only once.

Yeah, I always thought they were just trying to cheer him up, too. But then there's this scene from the KH2 manga:

 

http://www.onemanga.com/Kingdom_Hearts_2/12/31/

 

The manga doesn't follow the game exactly, though. So it could be true, who knows?

Haha that page made me laugh, i guess it is plausable but its strange seeing them grin like that, i mean a journey in space could last hours!

Haha that page made me laugh, i guess it is plausable but its strange seeing them grin like that, i mean a journey in space could last hours!

 

Agreed, that was cute! Well if it doesn't run on happiness, it must run, on...what? gas? Goofy's clumseness? or maybe the heart?

Most likely, since it's made of Star Fragments/Gummi Blocks it doesn't need a power source.