Not bad.
I don't write any music, even though I've thought about it before...
Even so, I love to listen to music like alot of people. I have a pretty good ear for it too. Not too fond of the 40-second (post-)intro, but it's popular with people so I won't bash you on that. I have a tendency to quit listening to songs when they get too repetitive, and it seemed every time I went to quit listening to your song, it varied some, so I'll give you originality. After the cooldown, around 2:05 the laugh seems a bit out of place, but I guess if you didn't put it there it'd seem too empty. Also the sound effect string starting at 3:27 seemed a little awkward. Maybe a different sound effect with the same pitch? Anyway, overall very satisfying. Nicely done, Good job.