Second what RetroTeddyBear said. The way this developer usually works is that the current version is paid, but the previous version is free. The Genex Part 1 should be free now I believe. From what I understand, paying will net you access to the current update and the next two updates when they are unlocked to that tier. Or at least that is how I think it works (I paid at the $20 tier because I liked the first part that much).