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
Telefrag the Guardian
Neutralize Chomper
Kill Intoxigator while intoxicated
Use cheats
Kill an enemy by spinning your weapons
Find Lavender's secret
Find Dopefish
Find 'Wife of Intoxigator'
Find Rachael's secret
Watch the credits to the end
Complete all three episodes
Complete episode 3
Earn the 'Completionist' award
Reach E3MS
Reach E2MS
Reach E1MS
Complete episode 2
Get past wave 20 in Endless Mode
Get past wave 10 in Endless Mode
Get past wave 5 in Endless Mode
Open Duskworld
Earn the 'Untouchable' award
Beat a level on 'Duskmare'
Earn the 'Pacifist' award
Earn the 'Low Tech" award
Beat par time in a level
Complete episode 1
Find a "You aren't supposed to be here go away" sign