The "I have played these" collection is there to help me remember what I've played, and how far I've gotten in them. It includes games I've bought on other platforms, but not itch.io. Demos are also put here.
The rating system is based on my personal enjoyment of the game. It's a harsh system-a game rated 3 or 4 is not necessarily a bad game, and may be someone else's 7 or 8. A 10 rating are for games I consider to be absolutely phenomenal, that I think everyone should play. A 0 rating are for...games I think are trash in every sense of the word. These extremes are very rarely assigned. You are more likely to see 3-4s, or 6-8s.
Much of my enjoyment of a game is based on how good the story is, rather than art. So, you'll more likely see a 10 rated game with stick figure art and great story, rather than a 10 rated game with great art and a mediocre story.
Some games will not have ratings. This is because I played them so long ago, I can't properly rate them. A replay and an update is likely in the cards.
Note to self: check out Synergia when it comes out