Interesting idea. I will put in my two centsfor criteria such as:
Accuracy: Do the buildings appear to be true to their real-world counterparts?
Detail: When viewed from a reasonable distance (not viewing through an electron microscope, but something realistic for a flight), is the level of detail on buildings sufficient?
Textures: Do the materials respond to light appropriately? Are the colors accurate?
Cockpit: Are the instruments and systems working as expected? (This gets a little thorny for non-study-level aircraft.)
Exterior: Is it modeled in the right dimensions? Does it stand up to scrutiny from a reasonably close distance? (No jagged edges when zooming in.) Is it well-animated?
Textures: Do the materials respond to light appropriately? How are the colors? Does it stand up to scrutiny from a reasonably close distance?
Sound: How does it sound from the interior? From the exterior? Are effects from things like flaps, gear, and cockpit noises accurate? How about engine startup/shutdown?
Forr things that loop, like engine sounds, can you hear the loop?
One thing I’m on the fence about in the Aircraft section would be a rating for performance. On the one hand, it’s certainly important to know if something is or isn’t working properly. But you also run the risk of filling it with reviews from people who might say xyz is broken but didn’t know how to use it properly. (Though that probably happens today on overall aircraft ratings.)
I would also throw in that if someone gives a below-average rating on a particular item, they should be required to leave a comment about why.