hey. so im making this fpa in blender and the mouse look script works perfect in blender but when i pack it and export it as runtime it doesnt work.
everything works fine but the mouse look is lagging shit. and my pc is a 1400 dollar pc so i dont think it has anything to do with that.

This happened to me as well. Try using other mouselook scripts and I'm sure it will work. A good place to find is at blenderartists.org