Blendoku is a free^[1] puzzle video game for Android and iOS mobile devices^[2] developed by Los Angeles–based studio Lonely Few, which was founded by Australian developer Rod Green and Yeong-Hao Han. In Blendoku, players are given a grid of squares, some with colors provided, some not. A palette of additional color tiles is provided. To clear a level, a player must "fill in" the empty squares from the palette in such a way as to create smooth sequences of colors both horizontally and vertically.^[3] The game includes 475 levels, and additional levels are available as separate purchases.^[4]

Green and Han acknowledged that the game is not accessible to people with a variety of types of color-blindness and were working on a solution.^[2]

Kotaku.com called it "Unique and addictive".^[1] Gamezebo called it "A brilliantly simple yet challengingly in-depth twist on classic Sudoku." but stated that it's a "tablet game" because many puzzles are too small to play on a phone,^[5]