Nice! :D Oh, about files...
This is a good foot-tapper. Really good. The vocal interjection is a great addition, doubtless. :D
Now, just a quick word about the filesize issue. First off, only about 1 in 1,000,000 people can actually detect ANY audible difference between a 256Kbps and 320Kbps MP3. Seriously. It's not even worth discussing, the difference is so minute.
But in future, if your file's ove the size limit, don't panic; just contact Newgrounds direct! There are many Flash submission larger than 10MB, becaue they're GOOD. I'm sure they would've let this audio file in too. Anyway, best of luck in future! :D