I'd like to buy Machinarium but I'm deterred by the fact that I'm asked to disclose my address and phone number. What need do you have for that information ?
In fact, it's Paypal that asks that, not Amanita. I thinks this is obligatory for payment, or just here for purchases that may result to a delivery of the product to your home, which is not the case for Machinarium. So in practise, if you don't want to give this information, just fill it with false address and number, and it will work.