Honestly, these are very good! Attractive, vibrant palette and solid detail. Perhaps that's why you haven't gotten much critique, because these are quite solid already. What I'd recommend is perhaps reconsidering that reverse-antialias outlines (or 'selout' ) you've got going, I was never a fan and I haven't become one in my old age, but mileage may vary. In the same front, internally you've got some implied linework, where you break up the line, generally there's a lot of antialias conventions that you know how to use but for my money are a bit... automatic, for pixel artists? They're worth reconsidering. Taking a few colors away, disambiguating a few tightly detailed spots in your work might actually help convey volume more, but that's honestly nitpicking. Well done!