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