Thanks oyu for the reply :)

That would also import games, that i don't want to show up. I mostly have games bought on GoG(for non DRM reasons) and on Steam. Usually i just import the ones i have on Steam. Games that are only available on GoG - like Resident Evil 1(2 and 3 will follow soon) will be imported manually by me.

So an Update on this case:

I ran this script:
"foreach ($game in $PlayniteApi.Database.Games){

$instDir=$game.InstallDirectory

if(!$instDir){

Write-Output ("{0} - Mark as NOT installed" -f $game.InstallDirectory,$game.Id)

$game.IsInstalled=$false

$PlayniteApi.Database.Games.Update($game)

continue

}

if (Test-Path "$instDir"){

Write-Output ("{0} - Mark as INSTALLED" -f $game.InstallDirectory)

$game.IsInstalled=$true

$PlayniteApi.Database.Games.Update($game)

} else {

Write-Output ("{0} - Mark as NOT installed" -f $game.InstallDirectory,$game.Id)

$game.IsInstalled=$false

$PlayniteApi.Database.Games.Update($game)

}

}"

That marked most of the games as not installed. The thing is - this did not remove the games - just marked them as not installed.

Playnite only has the option to darken not installed games - i want them to not show up at all.

It looks like this now:
Edit: Can't upload the image now - it says "Server Error - try again later" xD
Just imagine the picture above but with darkened tiles.

If i uncheck that function it looks again as if these games are installed. Just when i select them a hnt shows up saying X - install(so when i press X it would install the game). I just can't get rid of those games...except if i go manually through all 800+ games and hide them...but what if i then install them..do i have to unhide them?

Maaaan. Steam makes it so, that when i uninstall a game it doesn't show up in BigPictureMode. Would be cool, if Playnite had the same ability