I think this is a great shot that reminds me of Breugel and those mass village green scenes. It is very busy with a lot for the eye to follow and take in. I see a lot of people have compared it to Where’s Waldo well I think it has the same fascination. A photograph on snow or ice is always tricky and I think you have reached a good compromise. Maybe if you had brightened it up a bit with levels it may have been more contrasty but if the snow had been blinding white it would have hurt your picture. I see no digital artefacts and the clarity is good.
I think people when they judged the photo wanted more evidence of movement and that is why I think Karen’s comment may have worked for you. A slightly longer exposure would have given you movement on the outside skaters while leaving the still of inner skaters and characters around the edge un-blurred. Your camera was almost fully open so you could have stopped down or even turned down the ISO.Your composition is straightforward and effective for this "full of drama" shot.
I like the textured look of this shot. Looks a little underexposed. Might want to brighten it up a little with your editing software. I like the fact there are so many people to look at ... could sit there and study the picture for 15 minutes, just looking a the different people and what they are wearing. Good luck. jacko 8