>>37324745Mostly uncanny shading and usage of black outlines.
And also, most have problems arising from being a big design forced into sprite - like too many details on things, weird bulbous appendages, lines going weirdly and crossing themselves messily (they may be distinct on large image, but not on sprite), perspectives being all over the place and so on.
Last but not least, some have designs that would fit neopet/digimon more than pokemon.