Here is the full list of all 30 DUSK achievements. It takes around 15-20 hours to unlock all of the achievements on Windows.
Beat a level on 'Duskmare'
Complete all three episodes
Complete episode 3
Earn the 'Pacifist' award
Earn the 'Untouchable' award
Find Lavender's secret
Reach E3MS
Neutralize Chomper
Complete episode 2
Telefrag the Guardian
Find 'Wife of Intoxigator'
Reach E2MS
Complete episode 1
Earn the 'Low Tech" award
Beat par time in a level
Find a "You aren't supposed to be here go away" sign
Find Dopefish
Kill Intoxigator while intoxicated
Find Rachael's secret
Use cheats
Kill an enemy by spinning your weapons
Earn the 'Completionist' award
Reach E1MS
Open Duskworld
Earn the 'Completionist' award in every level
Pick up a bar of soap in each level
Get past wave 5 in Endless Mode
Get past wave 10 in Endless Mode
Get past wave 20 in Endless Mode
Watch the credits to the end