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