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