I think that the crucial relevance of Psychonauts is to be found in what it represented for the history of video gaming, at an extremely critical time for the medium when such creative courage, set in motion by a genius like Tim Schafer, was exactly what was needed.
It seems to me that even to this day the gaming world is constantly torn between the motionless monotony of big productions and the often unheard voices of the indie world that bring forth a spirit of authenticity and real interest in the creative potential of interactivity, but there were times when innovative ideas and perspectives managed to meet the interest of companies, when it was in front of everyone's eyes that something had to change: it was in one of these moments that Psychonauts came along and turned everything upside down.
Psychonauts somehow managed to establish itself with nothing less than a lunatic idea, this hallucinatory journey into a universe of psychic worlds, populated by absurd characters, an insane variety of mechanics, and painted on the screen with such a powerful identity unthinkable perhaps even nowadays on a game of this scale; it is an extremely ambitious game, but one in which there is such an underlying coherence that makes it totally crystal clear in its intent: everything is where it should have been, everything manifests the exact care that has gone into it, it is a COMPLETE game in every aspect, and that is something that, again, to this day seems to be increasingly rare.
Psychonauts is a treasure that we should all keep in our hearts, an idea carried from start to finish with passion and talent, a work of art conceived and realized with the same spirit, and that is just funny as hell