Make the game speed up as the score gets higher. A suggested approach is that every time a row
is completed (and cleared) the game speeds up slightly, i.e. the blocks drop faster. (Do not
speed-up play too quickly. An average player should be able to play for at least one minute, but
the speed-up must be noticeable within 30 seconds.)
Decreases tick duration by 5ms every time a row is cleared. Haven't factored in going into negative values, so don't get more than 120 lines or else you'll travel back in time or something.
Make the game speed up as the score gets higher. A suggested approach is that every time a row is completed (and cleared) the game speeds up slightly, i.e. the blocks drop faster. (Do not speed-up play too quickly. An average player should be able to play for at least one minute, but the speed-up must be noticeable within 30 seconds.)