I just installed LSL6 on DosBox, the game is in some sort of low resolution mode and had no voice acting. I managed to fix the voice acting, but I can't seem to fix the low resolution.
Does anyone know how to fix it?

The game used to have separate installers for VGA and SVGA versions and for each language, as those are all separate programs only sharing the audio. The original CD has several folders for different resolutions and languages.
I didn't try the latest GOG installers, though, which even has a separate download for the VGA version.
I wonder why, since adding the VGA version would only add a few MB extra, barely worth a mention. But now, you have to download another set of the audio files, just to play the VGA version.