Players that had no way of checking out CastleStorm will now be able to play it all over the place as CastleStorm Free to Siege was announced for mobile devices. Rather than being a direct port of the tower defense game (that Andy loved), Zen Studios is opting for a free to play model making this their first foray into the dark and seedy world of F2P. CastleStorm Free to Siege will include four campaigns, 150 battles, four nations with their own specialties and unique abilities, eight hero characters, and brand new spells that are adapted for mobile devices. Android users are able to get their hands on the game starting today with the private beta testing. The rest of us plebs can look forward to CastleStorm Free to Siege later this spring.