Here is my Detailed Critique
Its good, the art style is excellent. Now get ready for my brutal critique.
1. Intro is a bit to long. in the world of the internet and newgrounds, you must assume your audience has a five second attention span.
2. Like the music, but then it got monotonous. You had a wonderful fight scene going on, and sound effects would have enhanced it. I'm not saying sound effects all the time. Just here and there.
3. The pacing of your film is the exact same through out the entire animation. You need to make your films act like a roller coaster. Having the pacing go up and down, fast and slow. This could have been created if there was a pause in the whole pace when the blue one falls onto the plat form down by the dragon. You could have drawn that part out a little and have him sit there and think about his situation for a couple of seconds while cutting the music (good place for water dripping sound effects and such). Then OMG!! THERE IS A FUCKING DRAGON!!
4: You had a lot of great crazy angles at the beginning of the film. With warped perspective and such. But then they kinda disappeared. Why?
5: Character designs are cute, but a little flat. If you made them pop more it would add so much believability to the animation.
That's mainly it. Animation is solid for the style that you are going for. I'm normally not a fan of fight sequences, but this one had story and a set up to it. So I'm ok with it. Mostly I'm being nit picky, but I'm just trying to help you improve.