From what we know of his personality, Good Cortex serves to be a mirror image of Cortex; kind, patient, humble and caring. He's shown to be just as smart as his evil counterpart, recognising and using the scientific name for a flower upon seeing it.
Being a tenth dimension counterpart, he looks like Cortex, but with a few differences. He's a short human man with a large head, which has a backwards facing N located on the forehead. He wears a lab coat with a backwards N on the left of his chest, as well as pants underneath. He also wears rubber gloves and boots. He's balding, with poofy, curly hair around the sides of his head as well as a tuft above his forehead. He also has an equally curly beard and bushy eyebrows. Another detail that sets him apart from his regular counterpart is a pair of spectacles resting on his nose. The colours of his clothes and other details are unknown, as he has only ever been seen in storyboards.
Presuming that the 10th dimension is a complete mirror of the regular dimension the rest of the series takes place in, Good Cortex is likely enemies with Evil Crash, though this hasn't been shown in any deleted scenes revealed to the public.
In an even earlier deleted scene, Good Cortex and Evil Crash, rather than being separate characters, would be the result of the Psychetron malfunctioning when Cortex and Crash arrived at the 10th Dimension, switching their personalities. Evil Crash would have to hurt Good Cortex until he went back to his normal state. Concept art shows him in Rehab Lab with Evil Crash.
- After the scene, a level would take place known as The Rehab Lab. This would have been a reverse of the doc-amok levels (where Cortex gets chased by something and we have to rescue him), named Mock-a-Doc (where we have to hurt Good Cortex return to normal Cortex). The level would feature Good Cortex running after a bunch of butterflies, rather than Cortex running from a hazard.