The MegaCorp Add-on for Stellaris has 10 achievements.
As a Corporate empire, have a branch office on 5 different empires' capitals
Be a biological Hive Mind with at least 1000 drone Pops
Build a Matter Decompressor
Have at least 4 fully operational Megastructures within your borders (Habitats, Ring Worlds and Gateways do not count)
Build an Interstellar Assembly
Build a Mega-Art Installation in a nebula system
Build a Strategic Coordination Center
Earn at least 1000 Energy Credits per month from trade
Have a planet with at least 100 Pops
I won the Galatron and all I got was this lousy achievement