Some comments:
Semicolonkid: Pretty crazy. Interesting how it is hard to tell it was made with 3D software. It reminds me a bit of the Bauhaus style, though I’m not sure why. (Btw, those purple things with red in the middle look like some body part to me)
oJB: Nice colour contrast. This makes me think of bullying, with the different piece in the middle, being looked at by everyone else. I can almost feel the pressure on the little pawn.
fcharr: I think the Yin-Yang has a nice mix of symmetry and contrast (not only on the visual level). Not sure if it was intentional, but the fact the the circles are not perfectly aligned gives this model a feeling of being “hand-made”.
DoriNori: Thanks for explaining the joke on the title, not sure if I would understand it otherwise
I liked the day sky (but shouldn’t the colours be flipped? Red near the sun and yellow further above?). Also, the trick with the water reflecting the night was really cool. But I think it should’ve reflected the mountains as well.
RayVelcoro: This scene reminds me a bit about the Fallout game (specially the funny poster). The yellow light was a nice touch. I liked the chaos with the wires.
TomZed: I liked the lighting. The architecture is also very beliveable.
Invenis: I loved the cold feeling of this image. That tree looks so lonely. The leaves are also very cool.
Maxime: Someone is going to get his throat slit
The characters are pretty well done, and the pose of the one in blue looks good. The pose of the one in red looks a bit strange to me, but making a jumping pose is pretty hard so that’s fine. Also interesting how you made both warriors to be left-handed. Just one thing: I see that the bricks on the wall are placed directly on top of each other (as piles). As far as I know, bricks are always placed on top of another two to distribute the weight. Or is your wall based on real architecture?
Photox: The lighting looks very realistic, which is quite amazing since you did not use an HDRI. The cabins look quite dangerous! (Also, nice example of radial symmetry).
purbosky: Nice ships, but I think I liked the one with arrows on the front better than the huge one. Also cool how you aligned the ships to the nebula (the nebula could be brighter though).
lolwel21: Those clouds are really impressive, I really liked them. I just think that, since the scene is mostly white, some additional contrast with the shadows would’ve helped me to see the details on the clouds. Also, the red balloon was a nice touch.
wecampbell: Beautiful colours. I liked the white column in the middle, it gives the scene a certain “fantasy” feeling. I just think the water should be a bit transparent close to the foreground.
Nikos096: Cute buildings. Are they placed in any particular order? I thought it was chronological, but the Mayan temple should be older than the Eiffel tower.
joshwinkler3d: Interesting house. Does it have two kitchens?
I think the door is missing a handle.
Iridesium: Cool guys don’t look at explosions. I really liked the explosion. The superhero is also cool, but his pose makes him look “though”, while his body is more of a nimble hero. I think you could either add more muscle, or give him lighter guns (grenades or melee weapons would fit him better, I think).
didierv: Robot soccer, however, isn’t. Though watching an AI play against itself might be a bit boring. Did you consider to make a close-up of the two robots in the middle, with the scores in the background instead? Also, funny idea 
tklein: The hand-drawn effect is pretty cool. I liked how the thing (is that a necklace?) is very chaotic.
str11: Very mysterious and futuristic. I loved the contrast. Though I have no idea what this is, it reminds me of aliens.
Piet: A need that Suzanne candle. That would be so funny! Anyway, the molten wax looks pretty cool.
beau11: Very pretty butterfly. The grass field is cool, but the scale feels very wrong. I would guess that the butterfly is as big as my forearm! Either that, or that grass is thinner than my hair. I think in real life the butterfly would be about as big as the flowers.
DM9: I really liked the contrast, both white-black and smooth-rough. The sculpture reminds me of an hourglass.
RC12: The mountains look pretty nice. They remind me a bit of Skyrim. However, at the points where the mountains meet the ground I can see some clear seams. Not sure how easy it is to fix that with ANT.
caz747: The ring around the gate is pretty cool. Looking at some images, this looks fairly close to the “real” one. The scene just feels a bit empty though.
FlyingBanana: Patrick is getting really lazy lately! I liked the little dots on top of the starfish. Is it bump or did you sculpt it. The sand looks nice, but it is a bit too dry considering the water.
OLG: Pretty crazy. I’ll just believe you that this is related to symmetry 
Helge: That fish is pretty funny, specially with the pig nose. I can almost feel they swimming. I just don’t understand the relation to symmetry. Is it because the fish is symmetric?
RoberT: Speaking that title makes me feel like a snake
I find it really impressive how it is hard to tell what is geometry and what is shading in your entries. But I’m afraid I couldn’t sense the symmetry here, maybe because it is secret.