Convert gg to pdf Online: gg2pdf

You can use Tom's Editor to easily convert images from
Koala Painter 2, packed .GG to Portable Document Format .PDF.
Tom's Editor is a free, online image manipulation and converter program.

Go to Tom's Editor

GG

Koala Painter is a Commodore 64 program do edit images. GG images are packed using RLE compression.

PDF

Adobe PDF format is the most popular document format. Overcomplicated. Offers compression.