Destroy All Monsters was goofy AF.
Mecha-G is alight with me. However, in this current Monster-verse time-line, the current technology doesn't appear to be advanced enough to support the sudden appearance of a Mecha-Anything. My thinking is if they did have that technology then why haven't we already seen appearances of smaller Mecha's first, yes?
Unless, G/KK take place in the distant future?