Penguin Solitaire is a modified version of Freecell with 7 freecells, but more constraints on building the columns. You have to build the columns down by suit, so it's more challenging to move the cards around. Also it has an odd little feature where the suit piles start off with a random card placed in the first 3 piles. The 4rth card of that suit has to be taken from the columns to start the last suit pile. Because the suit piles can start off with any card, you can wrap from Ace to King when building down the columns or building up the suit piles.