Apps not in my app store

Hi,

I have a US app store account...and have noticed that games aren't in my app store. I wonder if anyone else has encountered this?

For example i can't seem to find,

Merge Flowers vs Zombies

GI Joe

I wonder if anyone has encountered this and if they have recommended fixes? I have looked on both ipad and iphone and can't find the games.

Thanks in Advance!

chong