It seems worth noting that many ideas seen as "playing god" (i.e. altering nature without a sufficient understanding of its systems) and ideas seen as similar to playing god could be problematic, though not in the sense many may assume.

Due to systems being holistic, trying to add, alter, or remove certain components of nature (the human body included) in certain ways is likely to create a systematic imbalance and result in negative consequences which may not be immediately known. It has happened many times before, and nature can be especially complex.

One might argue humans are part of nature, but we also have abilities granted to us by our prefrontal cortex.