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.
Faux Symbolism: The official companion book, Gumby: the authorized biography of the world's favorite clayboy, written by Art Clokey and others. Basically, Gumby's mind is free.
Getting Crap Past the Radar: In the 1980s episode "All Cooped Up," Tilly the chicken is kidnapped by the Blockheads and taken to an egg factory. She asks the hen in the coop next to hers what it's going on, to which the hen responds, "It's hell, Tilly!"
Ho Yay: This may be a bit of a stretch, but has anybody noticed that Blockheads G and J are never apart? And that J seems to take G's abuse a bit too submissively?
A piano-playing boy in "Small Planets" who goes feral when his arpeggio is interrupted. The boy sounds like a kid in the 1960s even though he transforms himself. In the same episode repurposed for the 1980s, the boy now sounds like a young man, at first, but when he transforms into a beast, his voice now sounds very deep, beastly, and menacing! Scary!
In certain scenes in which Gumby and the other characters walk or drive into a book, the animators used different models for the characters and vehicles. And these models were either crudely made or 2D!
The same goes for the shrink/growth episodes. In the 1960s episode "Chicken Feed", the growing effects with Tilly the chicken are created with badly colored two-dimensional pictures of Tilly. Also, in the 1980s episode "Shrink-a-Dink", the growing/shrinking scenes (specifically with Gumby, Goo, Prickle and Professor Kapp) used crudely made models in each frame.
Tear Jerker: The 1988 closing credits' music, which is enough to make kids tear up.