Here is the full list of all 27 Duke Nukem 3D: 20th Anniversary Edition World Tour achievements worth 1,000 gamerscore.
Find Sam in "Mirage Barrage".
Burn 50 bad guys to death.
Complete "The Birth" on any difficulty.
Complete "Shrapnel City" on any difficulty.
Complete "Lunar Apocalypse" on any difficulty.
Kill 10 bad guys in 10 seconds while on steroids.
Kill 5 bad guys with one shot.
Find Luke in the Level "Lunar Reactor"
Kill 1000 enemies.
Kill a Firefly Trooper while it's flying small.
Use the hookah in High Times.
Step on 40 enemies after using the Shrinker on them.
Step in a pile of excrement.
Find 70 secret areas.
Complete "L.A. Meltdown" on any difficulty.
Carry all weapons with ammo at once.
Use the Incinerator
Listen to Developer Commentary (Use at least one trigger).
Use a cheat code.
Kill every enemy on a level.
Finish a secret level.
Find the Doomguy in the Level "Death Row"
Tip an exotic dancer.
Finish the "Hollywood Holocaust" level in under 3 minutes.
Finish any level on "Damn, I'm Good" difficulty.
Find a secret area.
Complete "Alien World Order" on any difficulty.