In Belgium, André Franquin is an icon among cartoon authors, the creator of, inter alia, Spirou et Fantasio (Robbedoes en Kwabbernoot, in the Dutch translated version) and... Gaston Lagaffe (Guust Flater). "Une gaffe", "een flater", is a screw-up, a blunder, a goof (cf. Goofy).
The cartoons are old (created in 1957) and they constitute a weekly running gag (of a half or one page) about an office boy. He "works" at the offices of the cartoon journal in which he appears (Spirou), and if he is not sleeping, he spends his time inventing totally useless contraptions. He likes to economise, and he is environment-friendly when no-one ever thought about it. Hence, he drives an ancient Fiat (at least, I believe it is a Fiat) so as not to spend money on a modern car, and he has converted the engine to coal (!) - a World War II necessity when petrol was scarce - so as not to pollute by burning gasoline and to save money. Obviously, the car (when it runs, as it always breaks down) pollutes unbelievably and coal is much more expensive than petrol if used for this purpose.
This illustrates perhaps the difficulties a director is up against when he tries to transfer the gags (there is no real story) to the screen. I doubt whether many young viewers know about coal gas, and where would he buy the coal?
So, Martin-Laval has tried to modernise the environment and the gags. He has - predictably - succeeded only partially. Nevertheless, the actor who plays Gaston (Théo Fernandez) remarkably resembles the character, with his typical slouch and attitude. Gaston's impossible pets (a cat, OK, but also a grouchy seagull and a goldfish) are (not too good) CGI.
Try to imagine keeping a seagull as a permanent pet in an office. This was Monty Python before it was invented.
The purists baulk, of course. But if one keeps in mind that this is a children's movie, the makers have not done a bad job. It is good for some laughs, even for adults, if one suspends disbelief.
I do not know what the reaction would be of someone who is not familiar with the cartoons, but it may be problematic. I believe this is also the reason for the failure of Tintin as a movie. The connoisseurs hate it and the rest of the audience lacks the full background of the stories.