Alternate Winlogon program

Dear /prog/

I'm writing a program to create an alternate way to log on to windows (instead of a password, you have to win a tron lightcycle type game). Where do I go in windows to change the entry box to this game? I know it's possible, because I've seen those display models in best buy with facial recognition logins from the webcam.

Love, Anon

Pic mostly related.

Anywhere that I could go to learn about this?  I've tried technet, but I was unable to find anything useful (though I may just have tard search skills).