I feel that’s one of the best ways to grow the Fediverse further than it already is.
What I’ve seen happen is that someone with an interest in a more niche thing here will create a community for it, actively post in it for a couple weeks, and maybe a couple other people will post in it a couple times too, but then the creator loses interest or lacks material to post, and the community sits with old posts months old.
Not to dissuade you from making an attempt at creating those communities, but it’s just a little hard to sustain them without active participation to keep people coming back and growing.
You may even find that there are some active communities for games you’re interest in, but may just have trouble finding them. The best way I’ve found to discover communities is with Lemmyverse, using the communities tab at the top.