Why is it that games with good renders get bad reviews on F95. People play the games for free yet complain. Sigh, first world problems.
You realized that renders don't make a game being good? The game can have the crapiest renders and be good because the story, gameplay and replayability.
The comment about that we can't give a bad rating because the game is free is really stupid and old, If a game is good it will get a good rating, if is bad, it won't. I can apply that to steam games, if I bough a game I can make a bad review because I payed for the game even if I enjoy it. Because from your point of view looks like we can only do the opposite, if the game is free, don't complain, if you buy it, you can complain.
And the review system here works like any other in the world, people rate the game and let a comment why they liked and what not, is funny that most of the times the 4 or 5 star reviews are, "I love the story, is unique, the game is really grindy, have ton of bugs, but I don't care 5 stars" and the 1, 2 and 3 stars explain why the game is not really good and what can be improved and give examples.
You should read the reviews and not see how many stars the game have and if the renders are pretty or not, in that way you will understand why the rating and if you aren't convinced, play the game for yourself and give a review.