The dropping action would simplify user controls as the game would only require right and left buttons. Your 'counter' as you call it, for whatever reason you call it that, could just sit on the top row. Coding wouldn't be too hard, just more if statements. Maybe make arrays for each column, and just check if each position from the lowest has been changed to whatever color you're using as 'filled' and if so, change the next element in the array.