Using a mouse as a controller

[LunaMoo]

Sensitivity and smoothing settings of the PPSSPP will NOT affect how it behaves in game, however it does alters how PPSSPP itself maps values, to obtain what you have by using external program to simply map one to another you have to set smoothing to 0.0 and sensitivity to 1.0. Personally I find default values better for cases where I would actually want to use mouse like games which uses thumbstick as real analog, definitely wouldn't have fun trying to use mouse to simulating a press of 4 face buttons as that just sucks to anyone which actually is used to real PC shooters.

Overall the only almost-real-mouse-aim in PSP games is currently available in Metal Gear Solid Peace Walker with right analog patch and an addon to make it highly oversensitive.
Most PSP games did not even had a proper analog support and even the thumbstick was commonly used as 4 to 8 directions + acceleration, you have to continuosly move the mouse and the movement of the camera will speed up over time depending on how long you keep moving it and NOT how fast you do it, it's not even close to be accurate without patching the game as MGSW is.