Can anybody tell me a PC FPS game that simultaneously supports XBox 360 controller and mouse? I would like to be able to have smooth arbitrary walking with the gamepad joystick while simultaneously using mouse-look.

PS. The ideal game would also be cheap/free, have wide open areas, and have big lulls in the action (basically SkyRim with the proper controls).

A lot of games will do this, I know for sure Crysis (1 & Warhead) support the Xbox360 pad. However I don't think the sticks use analog movement. It just emulates the WASD keys I guess.

Just plain laziness. If you're going to support an analog stick why wouldn't you do analog movement? It would take the developers like a day (at most) to add that capability.

Anyway, I know at least SkyRim supports analog motion (probably because it was developed for console). Unfortunately once you enable gamepad support it completely ignores the mouse so you are left with lame joystick head motion. It would be nice to have the best of both worlds - analog motion and mouse look together. I've heard that some games support this - just don't know which ones.

You can emulate walk and run keys using a stick still, so you could still have 2 speed movement using an analogue stick. Realistically you are usually not going to need finer control than that anyway.

True, but I'm not actually trying to use a stick. I have other motives, and I just want a game for research that polls both Xinput and DirectInput at the same time.

Hmm, I don't know how smooth it would be, but you could use some kind of pulse width modulation to generate an average speed which corresponds to the analog stick position. e.g. Hold analog stick halfway forward, pulse the 'W' key at a high-frequency 50% duty cycle.

I have a vague idea to try something similar which would enable the player to look around using a headtracker, while continuing to travel in the same in-game direction. You'd detect how far the player's heading has strayed from the initial heading, and then pulse the WASD keys so that they maintain that original heading.

That pulsing is an interesting idea and could actually work. Especially if you linked up the walking and running hot-keys into the mix it might work alright.

Yeah, I think it all depends on how high of a frequency the game can receive key input. If it's limited to 10Hz or something it might be very stuttery.

Mirror's Edge and Valve games support xbox360 controller and m+kb at the same time and they have actual analog movement. If this will help with your experiment.