First of all, just as csh7 said, I do perfer your other flash game William and Sly to this one, but without comparison, let's take a look.
The controls were easy and basic, however, a little tedious in my opinion. Also, the jump was hard sometimes.
The artwork is brilliant and very well colour-coordinated, a beautiful mixture of blue, purple and green in the ocean and the sky was particularily admirable - however, the map, though nicely drawn, was complicated and the lay-out confusing. The Azurefish him/herself was a charmingly mystic character, however, not packed with too much personality. This is a good highlight, because it allows the player to stretch it's imagination in deciding what the fish, to them, is like.
Overall, this is a smooth-running and good quality game - light and simple, but occupiable enough and fun.
8/10 stars. Well done!