These are free Steam keys for Steam discount coupons, stocks are limited.
For Metro: Redux 50% off coupon:
1. Go here & create an Alienware Arena account if you don't already have one
2. Go here & login
3. Click "Get Key"
4. You will receive the key in your e-mail inbox
Follow the same instructions for the following:
XCOM: Enemy Unknown 50% off coupon
Dead Island: Game of the Year Edition 66% off coupon
Saints Row IV: Game of the Century Edition 50% off coupon