whoa dammit ninja'd by Jeremy,
I agree with Seiseki's points, and did this edit

completely agree with Jeremy he raises some good points on the anatomy too, but I can see how some aspects would clash to some degree with your anime aesthetic, but you can definitely adapt what he did to your intended style, (nice edits and design direction btw Jeremy

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with mine I just quickly was going to suggest a few more fins to reinforce what you were doing from the elbow
and larger webbed feet would be more practical, but if they are land walking a compromise between size and dexterity should be met.
some recommendations on the anatomical forms reinforcing certain muscles, you could argue that you want it to be flat for hydrodynamics etc. but as Jeremy highlighted strong muscular structure is required for swimming,
I think you should probably avoid scales as it'd introduce a few issues and possible style clashes, think more sharks smooth yet course/matte, and the tail could do with some work.
also on expectation I tend to agree, but if you do want to have a more red colour worked in, I recommend using the proven method of easing past expectation, if you
Establish the expectations you can slowly introduce things that would out of context look jarring, so for example when you introduce them (the player's first encounter) you should have them bluer and after you have established what they are, you can introduce variations, and the variations (within certain boundaries of course) would look more acceptable and believable to the player.
also I should raise that pixelling or drawing on pure white is a bad practice, think about it, when are they ever going to be present against white? unless on snow or some crazy white dream sequence, never. so you should get in the habit of having a relatively neutral tone, if not one that would be along the lines of what the background graphics or tileset would be. Having White as your BG can alter your perception of contrast and colour values to some degree, something that looks perfectly balanced on white, may look entirely out of place in it's intended context and require avoidable tweaking