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.
YMMV: The Groovenians
Anvilicious: And how! Basically, what it boils down to is "being a creative person is great, as long as you only do it for art's sake, because making money is for boring greedy people!"
Also, for a show promoting art and design, King Norman, the Normals, and the demonized Jeepers-denizens have some of the most memorable character designs, which mostly mesh with the show's limited CGI animation.
Strawman Has a Point: King Norman's song is about how everything has consequences and people shouldn't be expected to have fun all the time without paying for it. This has the unintentional effect of making him the most sensible and practical character in the cartoon. He also unintentionally points out that in the real world, Jet and Glindy would be considered welfare dependents at best.
Uncanny Valley: The bizarre character designs and the bad CGI help settle thing show firmly in the valley.