Amazon has opened Echo Button game building to developers with a new API called the Gadgets Skill API, which is currently in beta and will allow third-party developers to design and build games for one of Amazon's most recent Alexa-powered gadgets. While there aren't too many steps to beginning the game-building process there is one caveat to it, and that's the ability to buy the Echo Buttons so that you can work with them. These are only shipping to a handful of countries at the moment so this will likely limit which developers can work with them and which ones can't.
According to Amazon the Echo Buttons are shipping in the U.S., the UK, Austria, Ireland, and Germany, so it would seem that building games using the Gadgets Skill API will be limited to developers in these regions. Beyond that the next few steps seem fairly straightforward. Once you have your Echo Buttons ordered and they have arrived, you'll want to review the technical documentation and follow any instructions, then start building your game and eventually publishing the game. Like with other Alexa skills you'll need to be logged into the developer portal to build games for the Echo Buttons.
Now that the Gadgets Skill API is open to developers in beta format, this should start to bring more recognition to the Echo Buttons as a device. Prior to today's expansion Amazon had already rolled out the Gadget Skill API beta in a preview for early access to a small group of developers, which created a handful of games and experiences for the Echo Buttons to show what could be done with the new tool. This included experiences like Freedom Buttons, Alpha Buzz, Color Tap, and Horse Race for Echo Buttons. For the Echo Buttons to work, you will need to have an Echo device, such as the Echo, Echo Dot, or Echo Show just to name a few.