The recently released HEN for the EU Urbanix has been ported to US version of the game already! The instructions and functionality are all the same as EU, simply use the following save game data in place of what was released for the EU variant. Yosh has also helped us and injected the exploit directly into the US save game files, this means only one folder is needed.
Please stay tuned to the blog for many developments that are sure to come as well as updates and more. The game has also been removed from PSN and download lists worldwide. If you didn’t get it yet you are out of luck.
People who are on lower firmwares with a previous exploit such as Monster hunter, Super Collapse 3, etc… should stay there and wait.
Source : Wololo.net