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