Age of Empires: Definitive Edition

You cannot unlock this in a custom game but it can be unlocked via a custom campaign.

One option is to create one with 50,000 of all resources to start with. You will then need to build one of every building and research everything at each of them (use the 'steroids' cheat to speed this up) Note: certain technologies only become available once another technology at another building has been researched.

The second option is that there has already been a map created by Sky Maniac for several achievements that can be downloaded HERE.

For the details of how to download and install the scenario see THIS LINK