Not only did many blind gamers tell us how much they liked our first version of Solitaire, they asked us to create other Solitaire games, such as Spider Solitaire.
The goal of the Spider Solitaire game is to build cards in descending order: King, Queen, Jack, 10, 9, 8,7,6,5,4,3,2, and Ace in the columns of the tableau. Once you form this sequence, you can instantly move it to the foundation. Once you play all the cards and you have moved them to 8 separate descending sequences, then you win the game.
Spider Solitaire comes in several varieties, the easiest is where you use just one suit. The more suits you use – such as hearts and spades – the harder the game becomes.
At this point, Blindfold Solitaire had only two games in it, and they were more-or-less identical: Klondike one-card an Klondike three-card. It took a while to modify Blindfold Solitaire so that it could process several types of Solitaire games, such as Spider or Golf or Free Cell.
To make the game more generic, we had to create programming rules that described what actions are allowed on the tableau (must cards be of the same suit, or alternating colors), on the foundation (how many foundation piles are there), and the rules for the discard pile (can it be rescued and how many cards are taken from the deck each time). In all, we created about 30 rules to describe many variants of Solitaire.
At the suggestion of the testers, we created some new gestures that speeded up game play, and published Spider 1 Suit, Spider 2 Suits and Spider 4 Suits as in-app upgrade for Blindfold Solitaire. We added a cute zip-pop-bop that tells you that a card can be moved to the foundation.
The biggest request we had was the ability to undo a move. Keeping consistent with our other apps, and since it was a gesture that is not used that often, we selected a 3 finger swipe to the left. Gestures that are commonly performed should be one or two fingers; those that are rare can use 3 fingers.