Rating scale
Four ratings. No half stars.
No stars. I didn't enjoy it enough to be a fan. That's not a verdict on whether the game is good — it means it wasn't for me.
One star. I enjoyed it and remember it positively.
Two stars. I liked it enough to recommend it widely. These are the games that contributed something to how I think about the medium.
Three stars. Reserved for the handful of games where the experience went past a recommendation into something else.