Wow, I thought this review challenge died down, lol.
Onto your concern what counts a review/how long it should be, to be honest the minimum is a couple sentences and as long as it mentions something from the story. Like, "I love the conversation between x and y over z [then proceeds why]. You have a knack for dialogue" would count. If you have posted the links to your reviews here, then they would count. As for stories, it can be a one shot to a review of one chapter/several chapters. As long as it's a review, any story counts.
Since I'm here, does anyone want me to bring back the Monthly Reviewing Challenge? And if so, you guys still up for emblems or some other prize/incentive? I can do a new version/thread of this in June/July if there's any interest again and if we figure out how to keep this moving again.