The way the intro fades into song proper, and the way the song fades back into the intro melody, is really cool and the loop is incredibly smooth. Full disclosure, I didn't realize it was on loop at first. That said, the song could use a little more variety. If you added a second part to the song that was a variation on the first, and added something heavy to hit with the wubs(like something gnarly and bass-heavy), it would add some much needed kick and variety to the song. I don't know if your intention for this song is for it to be looped behind something, but after 2 or 3 repeats it starts to get old, and after much more than that, it gets a little grating.
I'm only giving you 3 stars mostly because of the length. You've got a really good idea here though, I'd recommend you keep messing with it and try to get it to about 2- 2.5 minutes in length. I personally would add a second verse(?) and an outro, but you do you.