The Good: Sporos is a free game with a simple concept and challenging puzzles. The Bad: With hundreds of levels included, the game is in desperate need of some variety in gameplay. As it is now, Sporos can get repetitive. The Bottom Line: If you like slower-paced puzzles, then this free download is worth a try. But don't expect it to keep your interest too long. Even with the in-app upgrade, the game can get repetitive. While some puzzle games like Bejeweled or Cut The Rope might require quick thinking and even quicker reflexes, Sporos is cut from a decidedly different cloth. This puzzler is more for the player who enjoys staring at a problem and weighing strategic options at a slower pace.Each level in Sporos starts you off with a field of empty cells and a designated number of seeds or "sporos" to use. Your job is to strategically place each of your sporos, so they end up "infecting" every cell on the field. As you can imagine, infecting an entire field of, say, 20 cells can be difficult if you have only two or three sporos at your disposal. What's more, different sporos can only infect cells in certain directions. So for instance, one of your sporos might only infect cells in a straight line, while another can do its work in an "X" formation. To play, simply drag a sporo from the top of the screen onto an empty cell and watch it immediately infect any other cells that lie in its infection path. From there, do the same with the rest of your sporos until all of the cells have been infected or all of your sporos have been used. If you've used all of your sporos, and the field still isn't covered, you can simply tap and drag the sporos to move them around. This makes it easy to quickly try different placement strategies. But of course, the more errors you make in your placement, the lower your score gets. If you get stuck, you can also ask for hints, but the game limits you on the number of hints you can get within an allotted time. What you'll quickly realize while playing Sporos is how repetitive the game can get. The puzzles get more difficult as you go, but for the most part, the gameplay stays the same throughout. With 300 hundred levels in the free game, it would've been nice to see, perhaps, a wider variety of sporos come into play or different obstacles appear on the playing field. There is a 99-cent upgrade available that unlocks the Experimental Lab with its mutated cells and other challenges, but even with this, I found myself getting bored with the gameplay after the first 50 or so levels. That said, I still believe this challenging game is worth a try if you're into these sorts of slow-paced puzzles.