Rules:
1- Play survival mode,
2- Get to the top of leaderboards,
3- Send a message on Community Hub or add me (profile: leandrro [developer]) so i can check stats
*additional rules
4- This promotion it is limited to 100 free keys total, after that the promotion is over
5- The same person, and/or Steam profile can not win the prize more than once
6- Only valid and verified results will be awarded keys