Only a 2/5? Talk about underrated...
The fact it was made back in 2002 means that this nice piece of work has been here for about 5 years with a low score... No doubt, the only reason this has a bad score is purely because it stars the Backstreet Boys!
The animation was smooth, the voice acting was pretty good, and the plot still works pretty well despite how long it's been here. No doubt, this movie has aged well! The character designs for the original characters were pretty good, and I don't care what anyone else says, the designs for the powered-up band members were pretty good, and the action scenes were animated very well. This flash especially stands out to me because after seeing so many "professional" shows on TV based on real people, and how they almost always tend to suck, it's somewhat heartwarming to see a masterpiece like this appear, despite the boy band hate keeping it down.
Doesn't look like you intend to continue the series, but if you ever do, or at least continue animating, good luck in all your future works! I have the utmost confidence that you will succeed if you ever decide to continue animating!