>>26 There are some differences, a few of them major, but as for expanding, it's the anime that does the expanding, there isn't really more of anything in the manga. Both Wenge and Kazama's roles are actually much smaller in the manga than they are in the anime.
It's weird, because like 90% of the time I prefer the manga to its anime adaptation, but in this case I really like the anime more. The manga is still totally worth checking out though. And so is the movie.
There's a bunch of small differences like how in the manga Smile plays with a Rubik's cube a lot instead of a game console or the order of some scenes.
There are one or two things though that I don't quite understand the reasoning behind changing/leaving out. One of them is that when Peco has his breakdown, quits ping pong and grows long hair he starts hanging out at an arcade. And there's a scene there that basically mirrors his introductory scene at Tamura's, where he introduces himself and challenges this dude to play a game against him. At the arcade though he introduces himself as Poco instead of Peco, which related to
>>25 is the name of another lesser known mascot of the same company. It's an interesting scene.
Also at the very end Smile's reading a magazine with Peco on the cover and mentions him in his conversation with Kazama, while in the anime he isn't really referred to directly even though it's implied that Smile read stuff about him online. It was kind of weird to leave their current relationship kind of in the air like that, though I have no doubt they'd still be friends, I mean why wouldn't they?