It is a great show, it’s just… variable. Some of this is by design, as a Jigen plot is going to be darker than a Fujiko focused episode. Every once in a while there will be an episode that’s pitch perfect and has a Spruce Goose (I wonder who directed that one?) but then the next episode is a bit lame.

Or there’s the version with better music, Cowboy Bepop. The tone is a bit darker because the Lupin analogue is age twelve but it’s still fun.

The TV series obviously toned it all down, but the first season is the closest to the original material - hence the bleakness and the crazy jazz score. Unfortunately it's also the worst one from a technical perspective, although it's one of the few products of that time that will continue to be watched probably forever, hence acting as a document.

I felt as the show went on, it became more and more silly, and I lost interest. I'm not sure how many episodes I ended up watching and at what point Miyazaki and Takahata left.

The movie is they directed was also very good.

I did enjoy the dark themed, somewhat recent spinoff "A woman named Fujiko", which is also recommended by a sibling comment.