Just wondering what resolution the game runs at...I think originally it only had 640x480 and 800x600, correct? So does the game as offered by GOG run in a small box, or can it be stretched to screen or anything like that? Thanks!

The original resolution is only 640x480. If by "streched" you mean run in full screen, of course; if you mean fill a widescreen monitor by stretching an originally 4:3 resolution to the sides... I'm truly disgusted, but also possible :P

Any game that supports fullscreen, even one running by itself will fill the screen as well as your video card and monitor allow it, and GOG's Blade Runner is running through ScummVM, which pretty much guarantees that it will have no problems with that.

If you have had problems with other old games showing a small image in fullscreen mode, there are video driver configurations that you need to change.

use scummvm's options to change resolutions
Graphics mode> OpenGL render
Stretch mode> pixel perfect
checkmark> aspect ratio correction

works fine on a 16:9 monitor with correct 4:3 as the original.
1920x1080