"Can't do a premium version, since there are ongoing server costs."
Care to elaborate why the costs exclude premium version? Why couldn't the paying users cover the costs, while the free play is basically your promotion tool (like Dropbox).
Care to elaborate why the costs exclude premium version? Why couldn't the paying users cover the costs, while the free play is basically your promotion tool (like Dropbox).
Ideally, Android needs a micro-payment system (tied to their service provider billing or something).