I'm now working on the game design. I decided to make my design document public, so if you are interested in what type of game this project will become, you can take a look:

docs.google.com/document/d/1LKae4bUVqUjsQlco2zMmO7EhaMlSS0-7Tgqf8vDlM1U/edit#heading=h.8sqzo6ck7eay

Feel free to comment in here.