This app was mentioned in 2 comments, with an average of 1.00 upvote
https://play.google.com/store/apps/details?id=james.monochrome it is downloadable in the Play Store. Be aware, the game isn't "published", as the Store says, so it can still contain bugs, and the gameplay isn't that long yet.
Well, I've said in another comment that I got a friend who is working a bit in his free time on an 8bit game. It's open source, and doesn't have any sounds yet as far as I know. You can contact him if you want.
Play Store link: https://play.google.com/store/apps/details?id=james.monochrome Github: https://github.com/TheAndroidMaster/Monochrome