For completionists, Portal offers a set of achievements that challenge your skills and encourage exploration. Some notable achievements include:
- Terminal Velocity: Survive a fall from any height. This can be easily achieved by creating a vertical portal loop (one portal on the ceiling, one on the floor) and falling through it for a few seconds before exiting.
- Long Fall: Fall 30,000 feet. Similar to Terminal Velocity, but requires a much longer duration in the vertical portal loop. Find a tall chamber and set up your portals.
- Transmission Received: Find all the hidden radios. Refer to the 'Hidden Radios' section for locations.
- Fratricide: Do whatever it takes to destroy the Weighted Companion Cube. This is a story-related achievement during Test Chamber 17, where GLaDOS forces you to incinerate the cube.
- Party Escort: Escort the Party Escort Bot to the Party. This is a humorous achievement related to the final boss fight. During the GLaDOS fight, if you manage to get the Party Escort Bot (a small, harmless robot) into the incinerator, you'll earn this.
Many achievements require specific actions or keen observation, adding replay value and a sense of accomplishment.