What is Psychonauts? Psychonauts is a 2005 action-adventure platform game series produced by Double Fine Productions and published by Majesco Entertainment for Microsoft, Xbox, and the PlayStation 2.

Psychonauts is set in a retro-futuristic 1980s, and follows Razputin "Raz" Aquato, an 11 year-old boy with psychic abilities, who ran away from his family's circus to sneak into Whispering Rocks Psychic Summer Camp1 to become a Psychonaut2. The series is centered on exploring the strange and imaginative minds of various characters that Raz encounters to help them overcome their fears or memories of their past.

There are 14 psychic powers in all of the Psychonauts games.
Psychonauts: Psi-Punch, Astral Projection, Psi-Blast/Marksmanship, Telekinesis, Pyrokinesis, Levitation, Clairvoyance, Shield, Invisiblity,
Psychonauts 2: All of the Psychonauts powers minus the shield, plus: time Bubble, Mental Magnet, Confusion, Mental Connection, Mental Projection.

[1] - A summer camp for children to hone their psychic powers, lead by Sasha Nein, Milla Vodello and Coach Oleander.
[2] - A Psychonaut is a spy with psychic abilities.

Information taken & paraphrased from the Wikipedia page and Mirahaze page.

Why Psychonauts? It's hard to articulate why I like Psychonauts so much. A huge factor in it is the art direction. The stylization and the way shapes are pushed are so fun to me; I love Raz's big 'ol head. The plot is very fresh too, I don't like I've ever seen another plot like it. A kid with psychic exploring literally and figuratively exploring people's mind? AND saving the world?! I'm so glad this game exists, it's such a nice breathe from the hyper-realism that's been happening.