Q: Is there a way to slow down or speed up my movement through the game?

A: Yes, open up the Main Menu and:

For ‘Classic Myst’ mode you can select the speed of the camera, if you want the speed to slow down drag the slider to the left, if you want it to speed up drag it to the right.

For ‘Free Roam’ you can sprint by using the ‘shift’ key, or you can toggle sprint on/off using the ‘caps lock’ key.