I've added even more challenges to the Mental Gym!

First, there's Instant Insanity (Java required). You've probably seen this puzzle before, and maybe even tried it. This puzzle was originally released around 1900, and was the Rubik's Cube of its day.

The other puzzles are Flash-based, and are also true classics. Try Lights Out, Towers of Hanoi and Planarity.

The last two I've previously discussed on this site. Back in September 2006, I posted several Towers of Hanoi videos. I first mentioned Planarity back in this July 2005 post.

You don't need to worry about being driven completely mad. As with the other off-site tests, I've included links to solution strategies on each of their respective pages.