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