Can I change the speed in game ? At the original it was F5 - F7 but in the gog version it doesn´t work.

Works for me though on the laptop i have to press fn+ f5 or f6 or f7.
Why it doesn't work for you i can't know
Am on win 10

OK, I didn´t press fn. I will try this later. Thank you

I tasted it and it works. FN + F5-F7. Thank you for the help

Okay but i tested it since i though i commented too soon and mixed things up and it happens i only need to press f5-f7 without fn. fn activates something else like at f7 i turn off the sound on my pc

Your can most likely change how the f-keys work in your bios so you don' have to press fn all the time

There's even a "hidden" ultra-speed option.
Just press Shift+F8 to have 8x the normal speed