This does not strike me as a scam. It strikes me as an amateurish start-up, but this is itch, where almost everybody is either an amateurish start-up or a straight-up hobbyist. They're probably hoping to grow their subscribers by promoting games for free until their subscriber base is big enough that they can sell their services.
I wouldn't give them an email address that I don't want to be spammed, but I wouldn't give one to Amazon or eBay or Paypal either. Email addresses are free. There is no reason for using the same one twice.