Basho Kioku is a fun memory game from the developers of Cursor*10 and xananeko. A grid of 36 tiles confronts you, and in each level you are shown a subset of those tiles which you can click. The goal of the game is to click every tile once, and just once, without running out the timer. Six markers can be used to help jog your memory.
A simple idea that is implemented well. I actually managed to beat it with a score of 11100. I credit Brain Age for my amazing victory!
(Source: Jay is Games)