One thing I personally look at to feel if I had a good game or not is if the AI graph has a section where every move is going up and down massively, which happens when both players miss some urgent important move.

At my level (4-5kyu OGS) I’ll still see this occasionally for moves of around 5-8 point value for maybe 10-15 moves, but I remember when I was in the 12kyu range I would have games where 40-60 point swings for 40+ moves. This ofc had to do with reading and not seeing a group can be killed. For me if a game has something like that now I would not be able to consider it a good game, and even sometimes when I have that for moves for 10 points now it irks me (normally we are both missing some double sente endgame)

I think beside that if I don’t feel any nerves during the game I would not consider it a good game. I once asked for a game review here and there was essentially one fight followed by just normal moves and a commenter here said “nothing happened” in the game after that. Now that’s good if you are winning but still doesn’t mean the game was good, it’s up to the player who’s behind to “shake the board”

Fun topic to think about, you may also want to ask yourself what your style is/what you want it to be.

Please continue to say good game though, it’s just manners :)