In random shots, Kaptain Skurvy's character model is missing its dark brown scaly skin from his body, so his entire torso appears the same light orange color as his belly.
In the second season, Candy would inconsistently but often appear without nostrils.
For the entire series, the island of Kongo Bongo looks radically different when it's seen from afar. Usually only the small seaside segment can be seen where Candy and Funky live, with a small forest and a couple mountain peaks surrounded by endless ocean on all four sides. In certain scenes though, both the jungle and mountains are missing, and the entire island is reduced to a small beach. The island has a large jungle with a swamp and a temple, a vast snowy mountain, a giant sandy desert, a banana plantation, Bluster's barrel factory, the crocodile's territory, and all the places where the other characters live, none of which are ever seen when the "full" island is shown.
From some angles, it's obvious that Donkey Kong's forearms are only partially modeled under his fur, and you can see where the arm models "end".
Often when Cranky Kong is shown from certain angles and we can see inside his vest, parts of his vest appear fully transparent because its CGI model only had one side.
Due to the early CGI tech, the show's animation is notorious for all sorts of goofs like characters' body parts clipping into each other, their feet sliding around on the ground or sinking into it, awkward deformations during facial expressions, or character models contorting in weird ways because if rigging limitations. The latter is most noticeable on the pirate crew, Captain Skurvy's chest tends to fold in on itself and Kutlass has a floating belly button.
Since the show's CGI couldn't render too many objects, every crowd shot of the Kritter army is obviously faked in some way. Most of the troops would be unmoving, untextured models or 2D sprites rather than full 3D models. When the Kritter army was supposed to move, only a couple of them would ever be shown in a shot, or their numbers would drastically alternate between shots.
Often when Candy Kong raises her head, small dark spots are visible on the underside of her chin, which are actually the same textures as her nostrils that accidentally got copied onto the bottom of her mouth's 3D model.
In certain scenes from season 1, a small random rectangle can be seen floating under King K. Rool's belly. Since the pirate Kutlass is just a copy of Rool's 3D model, he sometimes has the same oddity.
The entire series is notorious for its poor and primitive lip-sync, rarely do the characters' mouths correspond to the lines they say. This was somewhat fixed in the second season, which switched to a different animation studio and keyframe animation rather than motion-capture.
The limitations of the Crystal Coconut's hologram ability differ between episodes. One time Cranky in his hologram form can point at a real suitcase and "zap" it open. In another episode, Cranky sings an entire song about how holograms can't interact with objects.