No, i don't want to uninstall a app. I want to remove the app so that installer dont know that it is installed.
I have the old version of Labyrinth and i dont feel like i ever want to update that version to the demo version that you have to pay for to get more levels.
But since it is there in installer and want to be updated it would be nice to remove it so i dont accidentally update it. I guess/hope that there is some file somewhere that need some editing?

Either copy the application folder, uninstall the application (in Installer), then move the folder back in its place; or edit /var/root/Library/Installer/LocalPackages.plist