why is the game iOS only? does it feature mechanics that would only work on a mobile device?
Yes, being a puzzle game this relies heavily on multi-touch input for manupulating items, rotating them, manipulating several at the same time, etc.
Plus, developping a multiplatform project is a headache I'd rather avoid. :p This could be PC compatible, but it would require several compromises on the design, and I don't want that either.
If you were doing a free game it might be easier.
Clearly. But unfortunately this kind of game doesn't lend itself too well to a free2play model. This will have to be a so-called 'premium' pricing scheme. Which makes things a bit more complicated on the crowdfunding front right now..