I love the boldness of the style here, the rocket in front of the moon is delightful both theme-wise and visually satisfying to look at in how you used shapes & colors; the wavy border is also a really nice touch. The only thing I'm not sure about is the city below; more colors there or maybe more variation in shapes could've made the piece more visually cohesive instead of top-heavy.
Altogether this a really fun image, it made me smile!