The first unintended puzzle of this two-handed brainteaser is figuring out how to get started by extending its cylinder-like, connected, plastic gears from the compact shape they arrive in from the box without breaking anything. Pulled and manipulated straight, they measure 14 inches long. But, Coggy's 16 geared modules are high-quality and sturdy-and they have to be, considering the game is based on rotating them and folding them into shapes and designs to match the 40 challenges cards.

Once players get the hang of twisting the colorful gears this way and that, Coggy's concept is simple - which isn't to say doing it is simple. The visually illustrated challenges are separated into four levels of difficulty, from easy to extra hard. At first, even the easy challenges are tough enough. Some challenges use the colored-gear side of the Coggy; others use only the black-and-white side. Many of the colored puzzles include blank spaces where players can use any colored gear that works.

Some testers noted that the colors on the cards as slightly different from those on the toy. Once players agreed which was blue or purple or black, the brainteasing began in earnest.