I've been willing to make this topic for a while. Mostly, because of the direction some people are taking judging, and level designing right now.
Firstly, we need to get one thing clarified: Games and levels are works of art, and game/level designers are artists. By making one game/level, you are combining visuals, gameplay, story, and even music to create one single experience. It is probably the most complete form of art there is.
What defines art? As taken from a dictionary:
Merriam-Webster wrote:: something that is created with imagination and skill and that is beautiful or that expresses important ideas or feelings
: works created by artists : paintings, sculptures, etc., that are created to be beautiful or to express important ideas or feelings
: the methods and skills used for painting, sculpting, drawing, etc.
The bolded definition is the one that matters for us right now.
Imagination and Skill are both required when desiging a level, it's the combination of both that makes a good level after all. This definition highlights something important though. Something that is beautiful. Now, beauty is subjective; What is beautiful for one may not be beautiful for another person. Same goes for important ideas and feelings; what is important for me may not be important for you.
Art is not uniform: Art can be as complex as it can be simplistic. It can be as contrasting as it can be united. And all work. The subjectiveness is what makes art so diverse, and amazing. Art has a soul. Not a soul by itself, but the soul the creators poured on it to create. Their dreams, their visions, their view of the world, their thoughts, their skill. Art is everything and more.
Now, by showing what art is, I also showed what levels are, since they are works of art, as I stated earlier. And levels, just like art, have a soul. The way you convey the atmosphere through visuals, story and music, along with the way you want the gameplay to be; these make the soul of your level. It's not one or the other, it's never one above the other, but rather, both of them working together, united. Like a perfectly syncronized machine, all mechanisms depend on each other to produce the better. It is, again, the combination of skill and imagination.
And then, I get to the point I finally wanted to get. Judging. Rating a piece of art such as a book, a movie, a song, a painting, a level is already hard enough. You must look at it subjectively, and objectively at some aspects. Objectively is whether the work is well polished. But that's it for objectivity. Subjectively it's whether you like it, or you don't, and why. A good rating of a piece of work should be no more than this. Because it's your opinion, and no opinion is right or wrong, good or bad.
Speaking of opinion, you must accept that your rating is only that: An opinion. It's not a fact because once again: Art is all about subjectivity. Others will probably have a different opinion than you have, and they have all the right to. That's why in competitions like Drawing contests and LDCs, there at least 3 people, so each one's opinion equilibrate each other, to form an average of what they think.
So one last message for designers and artists. The only one that says whether your work is good or not, what it should do or not, what it should have or not, is yourself. Because in art, there's no "This is good" or "This is bad", but there's "I like it" and "I don't like it". There is always something to learn from reviews and ratings when it comes to skill, sure, but when it comes to imagination, the only limit you have is you. Never do your works to please others. Do what you like to do; have fun doing it. And don't let anyone stop you from doing what you like because they don't like what you do.
And this is all.