http://www.whoisphydeaux.com/movies/tetrishighscore.m4v Yes. It took a bloody lot of time. Yes, it doesn't really prove anything other than I have too much time on my hands.
I know, that's really aggravating. How would I have gotten that to work? Clicked Try Again instead of "end"?
From what I understand, you can't go past 99,999,999 or it glitches the record. So you either need to plan very carefully or get as close as you can without going over. If I were you, I wouldn't bother doing it again. And did you write on your DS with a sharpie?
For proof, fuck yes. Though I plan on doing a custom paint job in the future, anyway, and it'll be sandblasted, so not all is lost.
Don't worry, I did the 1,000,000 roses thing on 'We Love Katamari'. That takes even longer than maxing out endless. (About 40-50 hours or so). Yes there are a few rewards, but nothing which even comes close to repaying the time it took me. I felt pretty stupid for doing it afterwards as well.