While looking for a clear answer about how to get the ''Bad Ending'', I never really found something solid.
all were out of date, or some minor fixes.

The devs did leave a little clue,

"Basically, the more the main character opens up or tells the truth will lead to the bad ending. Think opposites, good=bad and bad=good."

A little experiment here and there with choices, seems like you only get the bad ending if you really do 1 correct walkthrough, 1 possible misplaced choice and you'll get the Good Ending.

But we don't want that one for now.

Now let's get started!

• Get the robot from Toy's Box.
  
• Sleep.
  
• Try to leave the room.
  
• Don't turn off the TV.
  
• Interact with the teddybear.
  
• Close the closet door.
  
• Leave the room.
  
• Open the drawer to get the screwdriver.
  
• Go to the kitchen.
  
• Answer the phone.
  
• Don't interact with the window.
  
• Take the batteries out of the remote.
  
• Combine the batteries with your toy robot.
  
• Pick up the lavender from the trashcan.
  
• Grab the ladder from under the microwave.
  
• Go back to the hallway.
  
• Put the robot infront of the linen closet.
  
• Grab the Postcard.
  
• Inspect Postcard.
  
• Apply lavender to mouse hole.
  
• Set up ladder on wall.
  
• Use screwdriver on vent.
  
• Go through the vent towards the bathroom.
  
• Take the spare key from cupboard.
  
• Don't pee in the toilet.
  
• Back to mark's room.
  
• Open drawer for a piece of picture.
  
• Back into the vent.
  
• Interact with the slot on the wall.
  
• Combine the 2 picture fragments.
  
• Go to the hallway.
  
• Open the office door. ( Right door )
  
• Put the full picture in the photo frame.
  
• Remember the code: 0419.
  
• Go to mom's room.

• Don't tell your story.
  
• Go inside the motel.
  
• Talk to Bill.
  
• Use the key to open your room.
  
• Go to bed.
  
• Leave room.
  
• Go to the reception.
  
• Interact with the key rack.
  
• Go outside.
  
• Walk right outta screen.
  
• Open bill's room with key.
  
• Interact with lawn mower to get blade.
  
• Interact with the workbench to get oil.
  
• Use the blade on trap door.
  
• Use oil on the blade.
  
• Again use the blade on the trap door.
  
• Go down.
  
• Interact with the tape recorder.
  
• Go back up.
  
• Don't give the tape to Bill.
  
• Go outside Bill's room.
  
• Take coal from BBQ.
  
• Go to the girl's room.
  
• Go to your room.
  
• Talk to the girl.
  
• Say NO to loving her.
  
• Go to the girl's room.
  
• Put coal in fireplace.
  
• Go back to your room.
  
• Interact with the girl to get lighter.
  
• Use lighter on fireplace.
  
• Interact with your toolbox to get screwdriver.
  
• Go to Bill's room.
  
• Use screwdriver on the power box.
  
• Use screwdriver on the washing machine to get car battery.
  
• Use car battery on the power box.
  
• Put the battery in the car.
  
• Go to your room.

• Go to the toilet.
  
• Cover smoke detector.
  
• Smoke.
  
• Go back to your seat.
  
• Interact with the intercom.
  
• Talk to the man with the newspaper.
  
• Go back to the intercom.
  
• Go down till you see a ladder.
  
• Go up and take the camera.
  
• Walk back to your seat.
  
• Take the camera to the man.
  
• Walk up.
  
• Attempt to open the door.
  
• Go to cockpit.
  
• Talk to the man.
  
• Go back to that door.
  
• Follow blood trail.
  
• Go back to the cockpit.
  
• Talk.
  
• Go back up till toilets.
  
• Open supply door to get batteries.
  
• Combine batteries with camera.
  
• Grab candy bar off the dead body.
  
• Go back to the end of the blood trail.
  
• Place camera on the box.
  
• Place candy bar on the vent.
  
• Go back to the cockpit.
  
• Pick up the gun.
  
• Go into the hatch.
  
• Talk to Mark.
  
• Interact with door panel to open door.
  
• Walk back towards cockpit.
  
• When Neason appears, don't shoot him.
  
• Talk to Mark in Cockpit.
  
• Get the monster downstairs.
  
• Become co-pilot.

• Go into the house.
  
• Go up the stairs.
  
• Enter the first door.
  
• Talk to Dave.
  
• Get the girl.
  
• Say YES to waste some time.
  
• Go to bathroom.
  
• Inspect toilet to get keycard.
  
• Go to the room where you talked to Dave.
  
• Inspect books to get keycard.
  
• Inspect the chemicals to get chemical.
  
• Go to bottom floor room.
  
• Inspect microwave to get jewel.
  
• Inspect the board to open up the painting upstairs.
  
• Inspect the cabinet with the yellow key above it for keycard.
  
• Go back upstairs.
  
• Go to painting.
  
• Enter the code: 0419.
  
• Back to hallway.
  
• Use jewel on statue.
  
• Go down.
  
• Use the keycards correctly.
  
• Combine blue + yellow to get the green keycard.
  
  After a while of talking you'll get the last option you need.
  
  
• DO IT!

You dead.

But enjoy your achievement!