So far I've been able to ask the following subs to add links to various comparable Lemmy communities:

https://www.reddit.com/r/tycoon/ (I am a long-time contributor here)

https://www.reddit.com/r/adventuregames/

Don't know if it makes much of a difference, but it can't hurt SEO.

I've also reached out to the citybuilder subreddit, but they ignored my message.

Some other genre-specific Lemmy communities that are active (unfortunately, it's mostly me posting, but not always):

• Automation Games - !automationgames@lemmy.zip
• Cozy Games - !cozygames@lemmy.world
• Incremental - !incremental_games@incremental.social
• Indie Games (variety) - !bside@fedia.io
• Lifesim Games - !lifesimulation@lemmy.world
• PC RPGs (cRPGs) - !crpg@lemmy.world
• Roguelike Games - !roguelikes@lemmy.world
• RTS Games - !rts@reddthat.com
• Strategy (RTS, 4X etc.) Games - !strategy@lemmy.world
• Turn-based Strategy - !turnbasedstrategy@lemmy.world
• Video Game Art - !gameart@sopuli.xyz
• Video Game Music - !vgmusic@lemmy.world

Help out if you feel like it or you are a regular on a relevant game genre subreddit.