Portal Stories Mel linux is a community made, free modification for Portal 2 based in the Portal universe.
It tells the story of Mel, who meets a new personality core and faces an undiscovered threat to the Aperture facility.1952, in the early years of Aperture: Science Innovators, Cave Johnson’s scientists experimented with whatever they wanted. Not everything worked as it should have though, but that wasn’t going to get in the way of the progress of Science! Mel unfortunately took part in a faulty test called the Aperture: Science Innovators Short-Term Relaxation Vault, falling asleep for years. When she finally wakes, there is a fake Cave Johnson telling her she needs to escape the facility and a new device called the Aperture Handheld Portal Device, her mind races with questions. “Who is this imposter Cave Johnson?” “What happened to the facility and its staff?”

“What happened to me?”

Main Features

• 22 levels, with an estimated gameplay time of ~6-10 hours
• Custom Story with 350 separate in-game voicelines
• Over an hour of custom music with the Free soundtrack included
• Huge amount of custom assets
• Standalone mod (You do not need Portal 2 installed to play)
• Logic based puzzles, not execution based puzzles

Incase you get lost/stuck somewhere, See this video playlist. It should help you with all your doubts.