It's so cute!!!
Honestly, you make it very easy to compliment your cover (and the story attached to it)! This doesn't feel armature in the slightest, I get the impression you've been doing this a long time. Sometimes I see artist's work and I think "yeah it's good, I like it a lot, but they have some ways to go still". However the only word I can use to describe this style in particular is "complete". Not to say you can't still improve more as an artist, I'm sure you have many surprises in store for everyone as you continue to make art.
And the composition!! UGh!! It's all so simple but in the best way I can possibly mean it! I hope you make more stuff in the future <3