It is very interesting art - really is fascinating.
You need to provide a value to a company by satisfying their needs in art and not merely what you want or feel like doing. If someday you run the show and are the game developer than you can use any art that you like. Until then, you must get in the developer and/or designer's mind, put on their shoes, to understand what they seek and you go create the assets that fulfill them.
Nice experimentation as you showed here is good in your spare time to improve your skills and maybe someone will request a print or two once in a while unless you market your work to attract sales. Usefulness of them for games, I would estimate at near nothing directly. You have the talent to change your whole prospects to good if you improve strategic thinking.