"Zero Time Dilemma" is notoriously popular for its challenging puzzles. The first puzzle in the game is no pushover, so here's how to seek your way out of the first locked stage in the game.

Examine the metal cabinets and you'll find a box of gelatin powder and (gasp) a fake leg. Grab the gelatin powder and inspect the metal cabinet to the right. You will find an iodine solution and a torso hidden in the cabinet.

Look around for the cardboard box on a metal shelf. The box contains a bunch of potatoes. A round part will be added to your inventory. Next, use the iodine solution on the potatoes to reveal these letters: DUDLLR.

Go to the glass cabinet. Open the left glass door by pushing the arrow buttons according to the letters you found on the potatoes. (down, up, down, left, left, right)

Behind the left door, to solve the fruit puzzle piece, just match the faces until the fruits and leaves match. Solving the puzzle will give you a mold.

Head to the right glass door and push the buttons again, this time in reverse order. (right, left, left, down, up, down). Grab the bottle of water inside. Now combine the mold, water and gelatin.

Go to the machine near the door and freeze the water and gelatin mixture using the thermo-fridge.

Once the gelatin is frozen solid, use that and the round part you got in the box of potatoes in the gingerbread man hole found on the machine near the door.

The drawer underneath will open up, which contains a key.

Go back to the left glass door and get the blue doll. Use the key to unlock the handcuffs and grab the right arm.

Return to the metal cabinet where you found the gelatin mixture, and open the other side. Unlock the handcuffs using the key. The left arm will show you a combination: 625. (It's not 529, you have to flip it to get the actual number)

Go back to the thermo-fridge and heat up the blue doll, which will turn pale and give you the code 1234. Heat up the right arm you found as well to open up the palm.

Add this up with the other combination you obtained from the hand: 625 + 1234 = 1859. Use this password on the device near the door.

Once you've keyed that in, you would need to authenticate using the right arm you heated up.

Congratulations! You found it!

Sources: Twinfinite | Sorumian on Youtube