After watching that Game Center CX interview with the guy who created Pokemon, I wanted to play some of his other games he mentioned. This game is so much fun. It is like concentration: the action puzzler. It says by Hudson Soft in this video, but really they just distributed it. It was distributed by Namco in Japan, but developed by GameFreak in 1989.
I love Picross games. The gameboy one was the only one I had not played. Within 2 hours of purchasing it, I had already completed all of easy and some of the regular mode. I hope I unlock more puzzles after beating both regulars, but if not, it was still worth $2.99 at least.