Here is the full list of all 30 The Darkside Detective achievements. It takes around 6-8 hours to unlock all of the achievements on Windows.
Slack off the job and read a trashy mag in each case.
Examine 8 cars.
Use the kango hammer on everything in the sewers before advancing.
Fully explore the vents
Enter the Cursed Lodge.
Take all of the Turner's calls in the Bloodwolf HQ.
Search 10 bins.
Listen to all of Dick Brickman's radio shows. Featuring Dick Brickman.
Listen to all of John's gags.
Complete the virus minigame in three steps.
Spot the Darkside SkyBeast.
Read all the book titles in the library.
Close case 7: Buy Hard
Play games in arcade
Remember neglected responsibilities
Take a photo at the photobooth
Check Roy's Alibi
Watch the credits to the end.
Close case 6: Don Of The Dead.
Close case 5: Loch Mess.
Close case 4: Police Farce.
Give Laxatives to McKing.
Close case 3: Disorient Express.
Close case 2: Tome Alone.
Close case 1: Malice In Wonderland.