I should verify this. Conducting a quick search in my mind, I don't recall a "Part 2" or sequel titled "Impact 2" for PSP. Most of the popular Naruto Shippuden PSP games include "Naruto Shippuden: Ultimate Ninja Impact," "Naruto Shippuden: Ultimate Ninja Impact 2 (International Version)," which is a separate version with different content, but not necessarily a direct sequel. The international versions often had added content, like new missions or characters, to appeal to Western markets.