This isn't a map, but a mod. It massively increases metal production by changing overdrive to be linear with excess power (rather than the square root of excess power).

This unbalances the game nicely. Turtling becomes easy.

source code available here:
https://github.com/WarrenWilkinson/zerok-bgh

It will be easier to find and play in the mods list: https://zero-k.info/Mods

https://zero-k.info/mediawiki/Custom_Modes