That was more moving then I thought it would be...very well done. And what a way to submit your first animation for newgrounds! ^^ You obviously got talent for animation and the voice acting was quite well done, so I won't comment too much on that.
The plot was quite interesting, I kind of expected the player to be turned into an enderman, now I feel extra sorry for creepers now >_< so good job with the twist, didn't expect it at all :)
But in all honesty your flash, while I found that it's shortness really conveyed the underlying message of pitying the creepers, I felt it was also a prelude to another animation/movie where something like this would be explored further. If you're planning to turn this into a series at all, it's a good start for sure :)
Nice work, sometimes the briefest of things, if they are well constructed and crafted with thoughtfulness can have the most poignant of effects on the audience. And you've got that in the bag so to speak...forgive me if I'm exaggerating. In any case I can't wait to see more from you :)