I really like these stylized studies you've got here. There's some good shape design that still adheres to the reference, while also having its own look and feel. You're showing a good understanding of proportions and are able to inject some energy into it! The only think I think I'd critique here is the smudgy value you have in the background of them. Having that kind of framing element is great and feels fun to do. But the values you laid in for some spots was too similar and muddied the presentation. Glancing at the drawings, I initially thought you had flat values because of it, until I looked much closer. Using the claw hand as an example, the little halo of highlight can feel necessary so that you're not stealing the shadow of that line. But it broke the illusion of highlight and depth when it then became that darker value for the background. Try looking at how artists you like using that sort of framing technique and why. We can see by cutting out the drawings and putting them on a flat value that you have a good value structure (Though you could push shadows even more). This doesn't mean your pieces have to be on single value background. You just need some consideration and intention for the background. Value is all about relationships of the values being presented so you need to take that into account too for this sort of thing.