Works. Not really my style, but it definitely works.
I know a toddler named
Genesis and everyone is always saying how great her name is. Though, to be fair, her family is Bible-themed in names. Dad is
Ezekiel (
Zeke) and brother is
Malachi.
They use the full
Genesis all the time too.
I honestly like Genny enough that I think it would make a bright nickname for an uncommon first.