Download Reshade (google it) and install the retroarch package (when installing reshade, it will show the option). Once installed, open the game and press "home" to bring the reshade menu and mark CRT_CX. On preference do as the following:

Scanline: 0.200
RGB: 0.200
Brightness: 0.500
Contrast: 0.550
Gamma: 0.600

If you're using a low resolution like 800x600 it will make the game look like the pic. If you want to make it look like this on high res, you will need to make some adjustments on those numbers.

Edit: sorry but gog is not allowing me to post imgur links. So I can't show the pics...

Edit2: the pics: imgur.com/a/oKMWjXg

Any way to make this work on Steam Deck?

Just leave out the 'https://' part of the urls - won't be clickable but you could copy-paste them at least.

If I recall correctly there's a requirement of 10 posts minimum before you can include working links.
Attached images cannot be larger than 450-500KB. Have to be in jpeg format too.

Heroic Launcher is good enough for this, install through there, you may have to remap the controls though, I seem to have a lot of trouble with controllers and this game.

If you want to use GOG cloud sync, the Heroic Launcher is the best option. However, if you prefer to install the game manually, follow these steps:

1. Download the offline installer from GOG.

2. Add the installer to your Steam library as a non-Steam game.

3. Launch it through Steam and complete the installation.

4. After installation, go to the game’s properties in Steam and make sure the path points to the correct Wine/Proton prefix.

5. Set a compatible version of Proton. I recommend GE-Proton 9.27, which works fine for me.

6. To fix input issues, add the following line to the game's launch options in Steam:

WINEDLLOVERRIDES="dinput8,dinput,ddraw=n,b" %command%

Note: Input handling might still be broken. You may need to remap all the controls on your Steam controller manually. Honestly, the controller issue almost made me refund the game—so keep that in mind.

I would add :

Bump Mapping, Vibrance, AdvancedCRT (HQ Scanlinies), use pixelated graphic + HQ4X on medium.
On top of it use Loseless scaling with adaptive frame generation for smoth FPS. (i use 46)

Thanks, it worked. Just posted the link.