BioShock Infinite on Steam
How to get your voucher
1 - Vote here (random vote works) Golden Joysticks 2015 | GamesRadar
2 - Create your account after voting
3 - Check in spamfolder for email (for me at least)
4 - Input your info here https://goldenjoysticks.greenmangaming.com/
5 - Receive voucher via email
Buy the game from here: Bioshock Infinite be sure to login using the same email you've received the key from.
Worked fine for me.