The PlayStation Portable, while a revolutionary handheld for its time, possessed a fraction of the RAM and processing power of the PS3. Porting Storm 2 to the PSP would not be a matter of compression; it would require a total reconstruction of the game's logic. The PSP utilizes a MIPS architecture, while the PS3 utilizes the Cell architecture. A direct "ISO" dump of the PS3 version is binary incompatible with PSP firmware.
The Ultimate Ninja Storm series (starting from Storm 2) was developed for PS3, Xbox 360, and later for PC, PS4, Xbox One, and Switch. The PSP only received Naruto Shippuden: Ultimate Ninja Impact and the Naruto: Ultimate Ninja Heroes series — different games with different gameplay styles (2D arena fighters, not full 3D Storm engine). The PlayStation Portable, while a revolutionary handheld for