I don’t think a 5/10 game is necessarily bad, but it needs to have some kind of - I dont know, character? Niche appeal? - to shine for the players who are going to like it.
I’ll throw out Krater as an example. It’s not great, but it has a unique setting, great atmosphere, and some interesting ideas driving it. I kinda love it for its eccentricities in spite of the overall experience being a bit meh.