Nirth: I found an old no-cd fix for this game that have a readme regarding unknown command lines for this game. The author didn't specify the reason behind the flag "-e" but it was supposed to say something about Direct Draw so just out of curiousity I added it to a shortcut to "sntrm.exe" and not GOGLauncher.
Now the game is not lagging anymore, it runs as quick as it's supposed. I've done anymore testing, but does anyone know how I could possibly use this "-e" flag in the GOGLauncher? I would like to play with both so I can see if one of them is more stable.
I also found this:
Sanitarium Error in Windows A user there mentions this:
if using win7 or vista, right click on the desktop, and click screen resolution. don't click on it anything, just leave it open.
Nirth: I tried this as well just out of curiousity and I was pleasantly surprised. The colour issue that is present in the game if you run "sntrm.exe" instead of GOGLauncher is gone. Something with DD issues regarding resolution in newer OSes but I'm no programmer.
If you're talking about the launcher from the Start menu you can add the flag just like you did for your shortcut as that's what the launcher is: a short cut with any possible flags applied :)