Here is the full list of all 20 UnderEarth achievements.
Pop the lid on 6 crawl spaces.
Complete the game by repairing the Core.
Fix all leaks in the Water Processing Plant.
Find a copy of "Zombies vs Toolbox".
Find an Easter Egg in the Console.
Packed a barrel and "shipped" it to the Lower Blocks.
Use the magnet boots on the magnet plates.
Load the toolbox to the maximum.
Play the game a total of 4 hours.
Complete the O2 Garden.
Solve the Queen Puzzle.
Put the basketball through the hoop in the promenade..
Crash through the skylight in the admin building.
Mess up the Core security puzzle.
Grab 100 objects.
Reach 1% Oxygen
Sacrifice yourself to destroy the Core and save the Earth.
Scan the Age of Blood arcade machine.
Find the CrackerJack easter egg.
Scan 10 unique objects.