I have a weekly board game meeting and I thought it would be fun to have the difficulty of the games change with every week. So like one week is light, then medium, then heavy. The light and medium week made sense, but then I discovered I had very few "Heavy" games.
A couple made sense, Millennium Blades and Argent: the Consortium still feel like a lot of thinking for me, even though I've played them a lot. But Spirit Island towered over my entire collection and I feel it is much easier to get into than the other two games. Also, Dead of Winter ended up in heavy games because of how I broke down the system.
I just used BGG's average weight metric to categorize my games. Light is 1.99 and lower, Medium is 2.0 to 2.99, and heavy is 3.00 and higher.
Maybe I'm just making the tiers incorrectly. Any ideas? Also, any discussion on what you feel makes a game "complex" would be fun to read about.