It seems that codes for Dark Souls: Prepare To Die Edition have made their way into Dead Island Riptide retail boxes in some countries. They are aware of the issue and will make sure the correct game will be attached to your account. If you had redeemed it and received Dark Souls instead, please contact Steam support. If you are getting your retail copy of Dead Island Riptide today, the code will work properly. Update: We've worked with Steam to resolve this issue.