Graphic Design for Game App

Hey, i want to learn something new and decided to start a project where im developing a game app. Therefore i need a little help with the graphics. Everything should be in a comic like style. I would love to have the option to get a few more models from the same artist with different styles later on, when im updating the game or so. But because i dont know where this brings me i dont want to invest in many levels at first. I need around 7-8 small astro graphics like earth, saturn, mars, metorites... Of course i can explain that a bit better in detail if you are interested in helping me here.