I like the category with subs beneath it idea!
Quoted from AMBoggs:IPDB is searchable by theme
Yes, but a lot of their catagories are so specific you can’t find similar machines sadly.
Maybe combine things so that animals and jungle are under “nature” or “natural” because they’re in the same vein.
Also add Novelty please!! I really love novelty games that are designed around big gimmicks: Orbitor 1, Baby Pac-Man, Nudge-It, Pinball Circus