Today I want to mention a possible way to measure quality of a game, following a model called TARGET.
For each of the attributes I have also added some easy questions you can use to measure them.

Theme: Is the theme enjoyable and close to reality? Are information on which game is based on realistic? Is the goal of the game consistent with the theme?

Aesthetics: How is material in the game? How is the iconography of the artefacts? What about readability of the information (cards, rulebook,…)?

Replay-ability: How your knowledge of the game can change the game experience? How many variants you can play? How many players combination?

Game length: Is game length consistent with theme? Are there some moments where some player is only watching? Is the flow of the mechanic fluent or start&stop?

Easy of play: Are rules clear and straightforward? Are there some weird exceptions to normal flow? Are there support to explain the game?

Tactics & strategy: What is the role of luck? Can player predict, monitor and control different phases of the games? Are players able to adopt different working behaviours?

You can measure each of these with a score 1 to 5 (or stars).

Here the link to provide feedback to one of the games.

Note. This model is inspired by Zee Garcia of Dice Game Tower