I’m guessing you’re using a mouselook script, and to limit the angle, you can either find one that does it for you, code it in yourself. It isn’t that hard, just a check of the angle before rotating.
To do this you enable the ‘save game as runtime’ addon in the user preferences, and then go ‘File -> Export -> Save game as runtime’
Use servo motion rather than simple motion. It’s a bit more complex to set up, but solves this problem. There is a tutorial on this at tutorialsforblender3d.com
Atually im using the arrow keys to make the camera look up and down since i havnt learned python yet.(but i plan to)Although is it possible you can you show me what the mouse script is?