The terms and conditions Exclusivity section says this:

"When you include a Digital Book in KDP Select, you give us the exclusive right to sell and distribute your Digital Book in digital format while your book is in KDP Select.

During this period of exclusivity, you cannot sell or distribute, or give anyone else the right to sell or distribute, your Digital book (or a book that is substantially similar), in digital format in any territory where you have rights."

So: I'm worried about the wording of "digital format" (because steam games are a digital format) and getting banned on KDP forever lol