26 March 18, 23:42
Humble Store is giving away keys for Hackyzack. But there are requirements!
1. When you collect five stamps on Humble Bundle, you'll get a free Steam key for the game Hackyzack.
2. To collect all the stamps, you need to visit the Humble Store link 5 days in a row.
3. You can also get stamps by spending $5 in the store.
link