These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
So Okay, It's Average: If you're more forgiving of the more abundant flaws, the film is generally mediocre with a few really good ideas that just needed better execution.
They Copied It, So It Sucks: It doesn't help that this was released only four years after Who Framed Roger Rabbit (Bakshi even said it wasn't an inspiration, but Paramount probably only bought his script because they wanted the same success as Who Framed Roger Rabbit).
They Wasted a Perfectly Good Plot: Despite/Because of how much of an abysmal failure this movie was, it raised a lot of questions that were never answered, the aforementioned Ass Pull and knowing the Executive Meddling, would've unleashed a pack of Voodoo Sharks to rival the end's onslaught of toons if given a sequel. We never know why/how Frank and Lonette hooked up other than an obligatory love interest/Pet the Dog, how many guys have been to Cool World since (or even before) Frank arrived since he implied Holli brings men in often, we don't know how often the above Ass Pull has been pulled (or if this explains Lonette's sanity, which just leads to a possible Voodoo Shark, itself,) why/how did the Death by Sex Rule come about when Holli and Lonette seem to be the only doable women in all of Cool World and... basically, when fanfiction writers can come up with better explanations and more compelling stories than what you've given your audience, you've fucked up royally.
There is a brief mention at the end when Lonette says something like "Do you remember all of those people who get killed by Doodles? They become Doodles themselves", which indicates that it happens rather frequently. But still...
What Do You Mean, It's Not for Kids?: Some people have managed to mistake this for a Roger Rabbit sequel. Boy, they were in for a surprise. Also happened in-studio, as according to Bakshi, "Kim Basinger had meetings with the producer and me, and thought it would be great – halfway through the picture – if she would be able to show this picture in hospitals to sick children… I'm dead serious."
WTH, Casting Agency?: Although he did an adequate job portraying Jack Deebs as a total wuss, Gabriel Byrne isn't most people's idea of what a gonzo underground cartoonist who hates humanity and wants to live in a world of cartoony chaos and sexy cartoon women looks like (someone who looked like or could make himself over like Robert Crumb would be more appropriate). Despite this, it's a lot better than the originally intended idea of Brad Pitt for the role of Jack Deebs, which would have been totally wrong.