"play" in this case does not imply that the product should be game or something like that but something that the user can interact with. From the Show HN rules:

"play" in this case does not imply that the product should be game or something like that but something that the user can interact with. From the Show HN rules: "On topic: things people can run on their computers or hold in their hands. For hardware, you can post a video or detailed article. For books, a sample chapter is ok"