Unlocked by earning the "What Cat?" achievement in Half-Life 2, the most humorous Easter egg in the game. However, the "What Cat?" award is unlike all of the others, requiring you to break the mini-teleporter in Dr. Kleiner's lab. To add insult to injury, the game doesn't lay out the process for breaking the teleport, forcing you to guess or simply get it right by chance.
If, however, you are absolutely keen on getting every single achievement in Half-Life 2, then you'd figure out you need to get "What Cat?" but not have the slightest idea on how to break the teleporter, this tutorial should finally be a guide for you to go by in case you've spent hours just trying to overload the little teleporter in Dr. Kleiner's lab.
Locating the Teleporter in Dr. Kleiner's Lab In "A Red Letter Day," Gordon Freeman escorts Alyx to the lab of Dr. Kleiner. The moment you enter the lab, on your left you will see the mini-teleporter. While Alyx and Kleiner have a little chat, you are allowed to roam around the facility playing about with the teleporter.
The teleporter isn't relevant to the plot, but it is necessary for you to pop Half-Life 2's achievements. Mashing on the button teleports things across between the two tiers, but for you to pop the "What Cat?" achievement and finally for the teleporter to dish out, you need to do multiple teleports.
To get the "What Cat?" achievement, you need to use the teleporter to transport objects across the two levels. The cactus plant that is on the platform can be teleported but larger objects like boxes will speed up the process. In order to efficiently pass objects through the mini-teleporter and cause an overload, do the following:
If you are using the cactus plant to break the teleporter, set it on top of the teleportation machine first before activating it. When a mistake occurs in doing such, the machine will continue to function but the plant will not be able to teleport to the other platform.
Even though there are two platforms on the teleporter, the activation switch is under the right platform. You do not need to walk to the other platform and back prior to teleporting the plant. Once sparks start flying from the teleporter and the machine no longer prompts you to interact with it, begin continuously teleporting the cactus plant between the two platforms.
The "What Cat?" award will pop up on your screen right before the teleporter overloads; it is a reference to the conversation between Alyx and Kliener that you probably missed since you were in a hurry to dismantle the machine.
This is all you need to know about How To Break The Mini Teleporter in Half-Life 2, just apply this guide and that's it.