The time for maxing out Tetris DS depends on how well you play. It took me about 5 hours to get 11 million score. So with that pace it would take me around 50 hours. But if you start at 20G mode and make tetrisses and t-spins you'll get there faster. I didn't made a lot of tetrisses.
I did achieve the 99,999,999 and it probably took me close to 30 hours (hard to say, it was over a 2 week period. I was pissed when it didn't save in game. I took photos though and recorded the last 1,000,000 on video. Anyone know if 99,999,998 will save? IE: if you stop right before you max it out, if TDS will keep the score? I saw someone with 12,000,000 in highscore, so I'm kind of wondering.
Tetris kiwamemichi is definitely maxable. It's a lot easier to max out the ps2 port, though. Arcade mode gets considerably more difficult, while home mode (default) is comparable with tetris DS, as it doesn't go above level 20. it maxes out at 9,999,999
