I could be wrong, but it seems that the people who made "Calvinball!" just wanted to have fun and did not take the making of the film seriously. Well, it may have been fun for them, but it wasn't really fun for me, the viewer. For those of you who don't know, "Calvin and Hobbes" is a comic strip about a boy named Calvin and his stuffed tiger named Hobbes. Hobbes seems to be a real anthropomorphic tiger when he's just with Calvin, but to other people, Hobbes is just a stuffed tiger. It's a funny and wonderful comic.
This film features live-action re-enactments of moments from "Calvin and Hobbes", but they're not well-made. The characters, including a girl named Susie, are played by adults and their acting is terrible. It seems that they didn't even bother to buy a tiger costume for Hobbes. It's just a guy with his face painted and wearing fake ears on his head. His clothes aren't even orange. That's Hobbes? He hardly looks like Hobbes! If you were to do a side-by-side comparison with pictures, it would just look funny, although probably unintentionally funny.
From what I recall, the re-enactments are usually(?) different from the comic. In this film, Calvin sometimes wears what looks like a Transformers mask. I don't know why. I don't recall Calvin watching the animated '80s Transformers show or even having Transformers toys in the comic. There also seem to be live-action re-enactments of moments from "The Far Side". Why? Again, I don't know.
The sound quality isn't good. You can barely hear what the characters are saying. Sometimes, they'll say something and I don't even know what they said. I did laugh maybe a few times. Like in the comic, Hobbes is a stuffed tiger, at one point, but he looks like the Winnie-the-Pooh character Tigger. OK, that's funny. However, I didn't laugh much while watching the film.
"Calvinball!" is cringeworthy, cheap looking, amateurish, and mostly not entertaining. Luckily, it's only about 12 minutes long. I think you'd be better off reading "Calvin and Hobbes" than watching this film.