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