As a player, it's a tough balance, since there are some that are broken; bugs that are easy to exploit that give a player an unexpected advantage and ruin the game for others.
Other IGMs are just poorly designed and, again, dramatically throw off the balance of the game. (Dark Tower, I'm looking at you)
Still other IGMs do almost *nothing* and are just annoying (Visit to Santa Claus).
I would avoid any IGMs that attempt to implement a whole new, involved, gameplay. I don't recall the name of the one I'm thinking of, but it involved earning some other form of currency so you could buy guns that you could use in the IGM. Just silly.
The best ones are the ones you can game to get modest improvements in your stats. There's one that's something Honeymoon Hotel (I think). You can get some modest stat bumps, send gifts to romantic interests, and there's enough to do that it's interesting without being out of balance with the main game.
GreenLFC º e>
greenleaderfanclub@protonmail.com
Infosec / Ham / Retro º masto>
GLFC@mstdn.starnix.network
Avoids Politics on BBS º gem> gemini.greenleader.xyz
--- Mystic BBS v1.12 A48 2022/04/26 (Linux/64)
* Origin: 2o for beeRS>>20ForBeers.com:1337 (21:2/150)