Can I use my xbox controller to play alien swarm?

I know the information page for Alien Swarm does not list it, but from the screenshots it seems like a perfect game to control with the xbox controller.

Did they just forget to add the icon or is it really not possible to use?

_{I guess I'm asking this question to somebody who has played the game}

It does require you to go into the console and enable the xbox controller. I've got it working fine on my game, I just need to figure out how to customize it because currently it is not allowing me to swap weapons via controller.

As of 2015, go

1. Settings
2. Keyboard and Mouse
3. Check "Enable Developer Console"
4. Open the console by pressing ` (backtick, same key as ~)
5. Enter exec 360controller_xbox (or try exec 360controller_pc)
6. Go back to Keyboard and Mouse settings to view or change the keybindings

Some related info: Using an XBox 360 Controller with Source Games

Simply type in console exec 360controller_xbox.cfg or if you're using the PC version of the gamepad, exec 360controller_pc.cfg to bind the joypad's buttons accordingly.

These files are located in C:\Program Files (x86)\Steam\steamapps\common\alien swarm\swarm\cfg\.