I'll try to find a few minutes to give it a go!
My controller is extremely cheap and generic, but I'll see if it works at all. :-)
I have noticed a bug with Unity and using multiple controllers that seems to only effect the triggers, which is used for throwing the snowball. If you disconnect your controller while in game on the title screen and then reconnect it, it should work. Also if you connect the controller(s) after starting up the game, it should work. Not sure why this happens. Give those fixes a try and see if you can get it to work. :)