By far, the most difficult puzzle we've ever come across! It's a bit like a Sudonku puzzzle on steroids. We know of only one adult able to solve the puzzle, although one of our kid-testers did manage to come close (34 out of 36 correctly placed). The puzzle uses different colours rather than numbers, but like a Suduko puzzle, there are six each of six different colours to position on the grid. The difference is that for this puzzle, you also have the added - 3rd - dimension of height to worry about. Each of the six same coloured pieces needs to fitted onto its own matching height of column, so that when the puzzle is solved, all towers are the same height. What all this means is that instead of having six different places you could position a given coloured piece, for this puzzle there is only one possible spot for each piece. Ridiculously challenging!

It's the most challenging brain teaser we have tested - the only brain teaser over the 3 years of testing that my son (14) hasn't solved by this point in toy testing cycle. Very challenging. If your kid is into this type of thing, it will really test him. Good for someone really into brain teasers and has the time and patience to finish it off - normally that would be my son, but he just got frustrated. Joyce Shane

To be honest, Peter (dad) was the only one in this household that enjoyed the game, but he liked it a lot, but didn't solve it. Denise Leuchter

It is too much like a rubics cube, but has the added inconvience of having lots of little pieces that could be lost. Elaine Eigl

Spencer (M8) does not prefer to play with these types of logic games so we could not get him interested in even trying the game. I definitely think it is better suited to older kids and adults. Rhonda Martin

I managed to get 34 of the 36 into their proper places. I could not do the rest. I found it very time consuming yet not so addictive as it's the same puzzle over and over again which you cannot solve. If you stayed up all day and night, you probably couldn't do it. Aryeh (M8)

For Serious puzzlers... How many towers can YOU place? Your goal is to place the 36 colored towers onto the puzzle base following two simple rules: there must be one and only one of each colored tower in each row and column, and the towers must fit in the base to form a perfect cube shape with all towers at the same height. Keep trying, see how many towers you can place before YOU get stuck! The 36 Cube is a diabolical challenge. Placing 20 towers correctly is hard. Placing 31 towers correctly makes you a puzzle rock star. Completely c=solving the 36 Cube is nearly impossible! We dare you to try!