Here is the full list of all 58 Day of the Tentacle Remastered achievements. It takes around 3-4 hours to unlock all of the achievements on Windows.
Get all other achievements in the game
Hoagie uses battery with Chron-o-John instead of plug
Ring the front desk bell 100 times
Reach yesterday without turning the stereo off
Flush 50 objects through time
Cook the hamster in Maniac Mansion (Don't try this at home, kids!)
Talk to Washington, Jefferson, or Hancock while they're outside
Laverne tries the chattering teeth on her human during the human show
Try to put something metal in the microwave
Try to flush the hamster
Laverne thinks about eating the cat
Try to microwave the hamster again after he's thawed out
Try to swap the textbook with the stamp album
Talk to Dead Cousin Ted with all three kids
Squirt five different people with disappearing ink
Try to mix the red paint and the Booboo-B-Gone
Try to mix the disappearing ink with Booboo-B-Gone
Try to mix the decaf and caffeinated coffees
Sit through the end credits
Play the whole game without skipping a cutscene
Defeat Purple Tentacle yesterday
Turn off the television
Power Laverne's Chron-o-John
Vacuum up a hamster
Get a tiny sweater
Pick up 45 things that don't belong to you
Close a door
Microwave the frozen hamster
Win the human contest
Disqualify Harold
Acquire a diamond
Get Fred to sign the contract
Return the stamp album to Weird Ed
Wake up Dr. Fred
Enter the human contest
Power Hoagie's Chron-o-John
Red makes a super battery with only a little help from Hoagie
Get all six novelty items
Make a skunk
Pick up 30 things that don't belong to you
Make vinegar
Clothe Laverne in the costume
Climb through the chimney with all three kids
Ask the IRS agents if they're related
Change the flag
Try to sign the contract yourself with the quill pen
Try to alter the contract with Booboo-B-Gone
Open the safe
Deflate Oozo
Try to wash the dirty car with the brush
Get a job
Play Maniac Mansion
Pick up 15 things that don't belong to you
Destroy a cherry tree
Create a cherry tree
Make it rain
Hoagie eats a Hoagie
Find Fred's basement workshop