I've linked some reviews here in this thread, short and long ones, as examples, maybe you want to check them out to get an idea what the reviews look like!
Generally, short reviews just cover my first impression and if I'd continue reading after what I was able to read in one hour (or less if that's what the person asked for, I just have to make a limit because the short reviews are free and I don't have that much free time)
Long reviews are more detailed and I'll go over the story chapter by chapter, as many chapters as the creator requested (and is willing to pay for )