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