Why can't I find certain game apps?

[iMore Question]

I live in the US, in Indiana. My buddies in the UK and Canada as well as here in the US can fin some games but others here cannot. I have one friend that went on about a game called "Deck Heroes" but when me and another fellow US friend of mine went to get it, we could not find it. I have been finding some YS friends and I can play some games but not others because they're showing only for some US friends but not us others.