It warps directly to the 18th level and fills half of the field quickly to be able to operate short distances in the top part of the field. From there on, it only gets tetrises (4-line clearings) until the score is maxed out.

A glitch involving pressing several directional buttons at once is used to manipulate luck for the next pieces. Flickering of the next piece block and piece in play results. Of course, the fun doesn't stop there, the L blocks also have their say in getting tetrises.

For the record, this is the fastest speed the NES game is capable of. For more extreme Tetris fun, please see movies from Arika Online.
There's some really awesome stuff there. (Click to download - 14 MB)

This run played on a real NES