You've got your colors down pretty well, but your blending in terms of the characters needs some work. By characters, I mean the fire sprites and the female character.
The background looks fantastic with this style. It's not too detailed to distract from the focal point, which is the character, though your composition does that a great deal anyways.
As per recommendation of improvement, I notice the left arm *from her side* >>> Right our's
is a bit wonky. The arm looks like it's broken and it almost looks like your tried to do a noodle arm thing *in reference to many cartoons*.
The primary issue with the arm, I feel, is the proportionate length. Elongated limbs are no real issue, however, it's best to keep the elongation consistent and based on the style you're going for. I'm getting Bayonetta/Tera vibes from this style, so I'd recommend using a reference from either of them as you practice.
The 2 primary things I'd recommend you improve on are your shading and anatomy, specifically with the arms and the hands. As per everything else, anatomically, I see no real issues in terms of your style.
As per your shading/blending, I would recommend watching a number of content creators on youtube (depending on the program you use)
If you use something like Paint Tool Sai, feel free to message me and I can lend you some brushes to practice with. A really good exercise is to draw some eyes and hands, then practice shading those with different methods, and choose the one that looks most appealing to paint with.
Please pardon any spelling/grammatical errors, as I am in a bit of a hurry while writing this. Either way, I hope to see you improve as an artist and I look forward to more of your work.