Many people have been stuck inside for the past several weeks and some are trying out voice games to pass the time or just explore the latest developments in voice-interactive entertainment.    Two games that have gotten a good deal of attention are The Vortex and the 3% Challenge, both from Doppio Games. These offer different examples of how to implement a game strategy on the leading voice platforms and serve as a jumping-off point for the conversation today with Jeferson Valadares, the co-founder and CEO of Doppio Games. We discuss these games in depth, how they differ creatively and from a business model standpoint. We also talk about monetization strategies, how voice revenue models differ from mobile and other gaming platforms and much more.    Jeferson brings a deep background in game development to Doppio. He is a member of the Board of Directors at Rovio Entertainment was formerly VP/GM of the BANDAI NAMCO Entertainment and also spent time at top tier game studios such as EA, BioWare, and Digital Chocolate.