To be honest I'm surprise this movie dosen't have a bigger cult fallowing, as it's one of more unique animated features I saw. It dosen't try to dumbed down anything for the children, create a kid-friednly world or try to have some a moral lesson at the end.
This movie is all about the humor and for most of the time - it's dark! 75% of jokes involves death or if not, they center around such topics drunkenness, religion (to be fair the scene in church is the best part of the movie), there are some non-PC stereotypes (heck, one of the Daltons calls a Chinese person a "Chink") and gun-play.
I for once strongly enjoy it! The animation is old but with great music and colors its creates a fantastic atmosphere. Characters are memorable, notably the four Dalton brothers and what I adore about it is how slowly the story builds - un-like the razel-dazzle cartoons we get today.
Over all - An underestimated animated film I recommend for any body who don't mind dark humor and a very unPC world.
P.S. And yes - If your a Lucky Luke fan you enjoy this movie a such as reading two or three of Lucky Luke books. It's just that good :)