This is on the Europe blog, but it mentioned Playstation Mobile is in US, Japan, etc. So I checked the Playstation Mobile and the game was free over in the US as well.
Samurai Beatdown is free for this week. The Europe Playstation Blog updates every Wednesday for you to check back each week. Just like any other digital game, you can get on, activate the free download, and then not download.
Hopefully Aqua Kitty is free one of these six weeks.
http://blog.eu.playstation.com/2013/...-starts-today/