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