Lately I've been going through a blog focusing on Combinatorial Game Theory, and right now he's at Dal 2016 highlighting talks about relevant games. I'm not familiar with very many of these perfect information games, but I see he'll often point out Nim variants.
https://combinatorialgametheory.blogspot.com
Kyle also keeps a pretty nice table of combinatorial games (and their properties) updated as new ones come his way:
http://turing.plymouth.edu/~kgb1013/rulesetTable.php
A lot of this is over my head, but I still find it interesting (and play a few games on the list).
I've been meaning to ask him about Hive, because it fits the mold, but isn't present.