The The Ancient Gods - Part One Add-on for DOOM Eternal has 7 achievements.
Complete Extra Life Mode with 5 Extra Lives in your Inventory (Ancient Gods 1)
Defeat Samur in the Holt (Ancient Gods 1)
Collect all physical Codex pages in a single save slot (Ancient Gods 1)
Complete all Secret Encounters in a single save slot (Ancient Gods 1)
Acquire all Support Runes in a single save slot (Ancient Gods 1)
Destroy the Life Sphere in the Blood Swamps (Ancient Gods 1)
Complete the UAC Atlantica Facility (Ancient Gods 1)