Drop 7 is a Tetris-puzzle hybrid. Their tag-line is simple, "Tetris meets Sudoku". And no other words ring so true when describing Drop 7. Tetris was a major hit for Nintendo's Gameboy and Sudoku is a culture phenom in Asia, but can Drop 7 win the hearts of iTouch and iPhone owners. 

Imagine a 7 x 7 grid, being populated by numbered discs, 1-7, as well as grayed ones. Each level is determined by the set of moves in one round, after the round is over, a single horizantal row of seven non-numbered discs are populated.

So, with each move random numbered and non-numbered discs are available to drop, the player has to break away the non-numbered discs as well as match the numbered ones for them to disappear.  

How does one break non-numbered and have the numbered discs disappear? This is where all your Sudoku play-time is put to good use. To have the colored discs dissappear from the board, one has to line up the respective discs in a vertical or horizantol row and the matching numbers in the row will vanish. 

For example, in a horizontal or verical row of seven non-numbered and/or numbered disc(s), the actual disc/s numbered 7 will dissapear from the board. In our example row of seven, if any non-numbered discs next to the disc(s) numbered 7 take damaged.

The non-numbered discs are colored grey, as the numbered discs have its' own respective color.  After two successful hits on the gray discs, it becomes a numbered disc. 

As discs begin to appear with its respective number and/or disappear, (as discs fill the open spots left by the dissappeared discs) with each drop combination points begin to increase in their size amounts. The crux of the gameplay is the string of combinations one can do within one move. The game ends when the board becomes oversaturate with discs.

With each line increase at the start of the next, numbered discs should poulate instead of all being closed grey discs. The addition of numbered discs at each level would solve the green 1 discs that creates a wall that becomes impossible to break.

Would give novices an easier time to break the wall and veterans incredible drop bonuses.

Rules are simple, the touchscreen is intuitive and the only hard part is quitting the addictive game. Drop 7 is a wonderful addition to the iPhone library of games and a true testament to the ingeniouty and freshness of the puzzle genre.