This is a one person game, a new developer. It is impossible to read a book or watch a tutorial series and then pump out a AAA game. I tried it myself, you can try it too, download Unity and have a go at it, it is hard and frustrating and we need to understand this and support someone that pushes forward and learns, I am sure the next game will be better and the third one will be better then the second one.
The time is not wasted, the developer learns while he is making the game and not everyone needs AAA graphics to enjoy the game, like we have text only games here so graphics are not a requirement.
My suggestion is to try the game if you can download and run it then let a fair feedback keeping in mine that is just 1 dev team and the game is at is beginning, the dev responds to feature requests if the is able to. So maybe you can be specific on what you think can be improved with the graphics while not shitting on someones efforts(it is really a lot of work for free so we should put a bit of effort in the comments at least IMO).
You mentioned renders, the images are screenshots from the game, sicne is a 3D real time game this means this images need to be rendered fast on screen like 30-60 renders per second, this means you can\t have same quality like renpy games where one render can take a lot of minutes. Anyway if you make a more constructive comment with details the developer would know what exactly is you don't like and explain if it can't be done, or if it be improved soon etc.
I hope you take my comment a some friendly suggestions and not as some kind of fight that I try to win points or score, I am trying to share what I know and improve the quality of discussion here and prevent the dev to get discouraged.