I guess, as a result of Tim Schafer's getting back rights on the game, Psychonauts just got updated on Steam. now it supports achievements, steam cloud and there is a Mac version. I don't know if there were any fixes, but if there were, i hope GoG version will get updated too^^.
P.S. I hope we have a chnace of getting a sequel now

Apparently they nerfed the Meat Circus.

There is some stuff in this article & press release

Great to see them do a Mac client, the only thing that makes me regret buying Psychonauts on GOG :) I use a Mac & hate booting into Bootcamp but not quite enough to buy the game again.

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Hey KainKlarden, nice to see another "New User" from 2008 :)

@tarasis
yeah, i'm not the most talkative user. still love the service and library, though