Ignoring the fact this is an NFT that has been copypasted multiple times, there's are plenty of flaws:

1. The black outlines are very aliased and wonky,
2. The helmet and sword's pixels don't align with the dolphin's pixels. Only do that with animation.
3. The sword's blade appears very stretched out,
4. That thing betwen the blade and the handle of the sword isn't aligned with the rest of the sword.
5. The sword's behind both fins
6. Very weird and uneven shading + lighting, like you were quickly scribbling with a mouse or tablet. Pixel art is usually a carefully precise process where every pixel should count. Otherwise just do regular digital 2D art.
7. You favourited your own submission when no one else did.

Why NFT tho

great job

there are no voxels in this image. tags are wrong, same with your other art