Full list of all 27 Duke Nukem 3D: 20th Anniversary World Tour achievements. It takes around 12-15 hours to unlock all of the achievements on Windows.
Use a cheat code.
Listen to Developer Commentary (Use at least one trigger).
Finish any level on "Damn, I'm Good" difficulty.
Complete "Lunar Apocalypse" on any difficulty.
Kill 1000 enemies.
Find any secret level.
Step in a pile of excrement.
Kill every enemy on a level.
Kill 5 bad guys with one shot.
Finish the "Hollywood Holocaust" level in under 3 minutes.
Complete "L.A. Meltdown" on any difficulty.
Tip an exotic dancer.
Find a secret area.
Complete "Shrapnel City" on any difficulty.
Complete "The Birth" on any difficulty.
Complete "Alien World Order" on any difficulty.
Step on 40 enemies after using the Shrinker on them.
Find 70 secret areas.
Find the Doomguy in the Level "Death Row".
Find Luke in the Level "Lunar Reactor".
Find Sam in "Mirage Barrage".
Use the hookah in High Times.
Use the Incinerator
Burn 50 bad guys to death.
Kill a Firefly Trooper while it's flying small.
Carry all weapons with ammo at once.
Kill 10 bad guys in 10 seconds while on steroids.