Psychonauts: In the Rhombus of Ruin is a 3D puzzle VR video game developed by Double Fine Productions for the PlayStation VR on the PS4, and on Microsoft Windows, SteamVR, HTC Vive, and Oculus Rift. It takes place between Psychonauts and Psychonauts 2. The game was released for PlayStation VR on February 21, 2017 and on April 19, 2018 for other VR Systems on PC.
Psychonauts: In the Rhombus of Ruin takes place immediately after the ending of the first Psychonauts game. Raz, Lili, Sasha, Milla, and Oleander head off to investigate the disappearance of Lili's father Truman Zanotto in a jet. Raz uses Clairvoyance on Lili's Music Box that her Dad gave her in order to help locate him. Raz discovers that Truman is in an underwater laboratory that houses a lot of the Psychic material known as Psylirium which can be harmful to Psychics. Sasha, Milla, and Oleander deduce that Truman must be in the abandoned underwater Psychonauts facility located in the Rhombus of Ruin. Just as the jet approaches the Rhombus, it's suddenly brought down and crashes.
Raz wakes up strapped to a chair and notices that none of his allies are around. Using Clairvoyance, Raz travels around the facility using the eyes of whatever body he lands in. He discovers that Milla, Lili, and Sasha were victims of Psylirium exposure which causes them to hallucinate. Raz eventually saves them all by playing music that they were each familiar with to snap them out of their hallucinations. When Raz locates Oleander, he's forced to flood the room he's in to make him stop singing and gives Oleander a fish tail bottom to allow him to swim. After pointing out the mutated fish guards, Oleander realizes that he likely knows who's in charge of the facility and tells Raz to run after hearing he's in a dentist chair. Just then, Dr. Loboto appears and states that he kidnapped Truman Zanotto on orders from another client whom he refuses to expose. When he turns around, Oleander sneaks in from below to hand Raz the Psychic Portal which Raz uses to go inside Loboto's mind.
On a boat, Raz has to help the First Mate Loboto find the compass needed to steer the ship and to fend off the attacks of the giant Monsto-Loboto. After defeating the Monsto-Loboto, Raz manages to go deeper into Loboto's mind to learn about his past. Loboto was born a Psychic, but his parents were disgusted and reviled by his powers and they no longer considered him their son. They eventually sent him to a hospital to get a Lobotomy which removed his powers and caused his insanity. Raz discovers the compass in the mobile above Loboto's old crib and gives it to the First Mate. After exiting Loboto's mind, Loboto's sanity is restored and he feels remorseful over everything he has done. He tells all of the guards to swim away and then sets the base to self-destruct before leaving. After Raz unlocks the restraints for the jet, the Psychonauts fly away with their mission accomplished and Lili tells her father that Raz is her boyfriend which leaves him shocked.
Being a VR game, In the Rhombus of Ruin will not be focused on platforming, like Psychonauts was, but will instead take a more puzzle-oriented approach using psychic powers such as Clairvoyance, Telekinesis and Pyrokinesis.
- Originally, Tim Schafer wasn't going to answer how Truman Zanotto was rescued believing that it wouldn't be as interesting as Raz entering Psychonauts HQ and seeing what it's really like. He changed his mind when he decided that would be too frustrating for the fans and he could make the rescue into a one mission game set in between Psychonauts 1 and 2.
- The game's opening and closing theme songs are a tribute to the bombastic theme songs of James Bond spy movies. In particular, it resembles the theme to the film Gold Finger with its smooth, droning horns and it's sultry female vocals.
- In this way, the game's theme is also similar to the theme for Metal Gear Solid 3: Snake Eater. A video game which also paid tribute to 70s-era spy films in its opening.