If you are having difficulty downloading them from the Play market, or another legitimate market like Amazon or GetJar, you can try clearing data and cache.
Go to Settings | Apps | All | [market name] and you will see the buttons there.
Another option is to clear data and cache in Downloads and Download Manager.
If all of these fail, use the email developer link in the preferred market to contact the developer and see if there is a reason you cannot get the game.
I hope this helps.