Yeah, ouch describes the jokes quite well. Franquin was great with lighter humor, adventure and slapstick too. After all his main works are all published as children's comic series, though they're really more an "all-ages" thing, where adults get the different levels whereas as a younger kid you read it for just the adventure or the slapstick. Later Gaston comics address some of the same issues, like the environment or militarism, but aren't quite so bleak. Like Gaston survives. ;)

The main reason I took French in high school as third language was because I wanted to be able to read French comics, but I've found out that reading comics is harder than reading regular texts, because there's fewer words for contexts (and it's not as if in modern comics the words say the same as the pictures so those aren't a lot of help) and they have lots of colloquial language and expressions, so my French never got quite good enough for comic reading.