Unable to move left or right with camera angle

Hmm... turning left or right is only handled by the mouse. If that does not work, is there maybe another program which takes the focus from the game? Is the mouse cursor visible while playing?
When opening the inventory, for example, do you see the mouse cursor? Is it the "Rising World cursor" (if you know what I mean), or just the default Windows cursor? Can you move the cursor and actually interact with the inventory?