Good job!
Well, truthfully, it was pretty impressive -- is this really your first frame by frame animation? It did turn out quite well then, didn't it?
The best part was actually the animation -- the happy faces seemed almost a little psychotic in how even when they were getting beaten to death or thrown around, they were still smiling. I'm not sure whether it was you being lazy or not, but it worked. :D
There wasn't much in the way of a cohesive story. This guy sort of walked around, beat people up, and then an alien started playing the guitar. I didn't really go for the sound either, because it was just so low... I had to turn it up to hear it at all -- the music wasn't very good either.
If this animation had a bit more sound, and possibly some more color, it could've been that much better... but it didn't, so I'm giving this a six.
A great effort indeed!