I know this can be done, I used to set the game speed to maximum back in the day, and I've seen videos of people doing the same, but for some reason the option is grayed out in my game. What's more is that gray out problem I've had once before and fixed it, but can't remember how.

Any help would be appreciated.

I found a solution: turns out, this game was made by Gearbox (it wasn't), because Borderlands 1 has the same issue.

In order to change the game speed one has to mouse over the the scrollbar in the options press Arrow Up key to highlight it, then use Arrow Left and Right to change the speed.