I enjoyed this quite a bit. The mixing fit in perfectly with the lyrics. I fucking hate Britney Spears but you managed to make something I enjoyed out of it which is not an easy task. The supression you put into the voice and instruments sounded awesome. You could have cut just a bit off the end because it started to feel a tad repetitive. Besides that it wasn't repetitive at all, it only felt like 3 minutes when it was almost six.
You got some talent there bro. This really popular for your first submission, it's got the amount of downloads it takes me months to get. I've never actually heard of Cubase 4 which is weird but it sounds like a good program.