To unlock all characters and enable the "SFIV style" juggle system, you need PPSSPP cheat codes. Download cheats.db and place it in your PPSSPP/PSP/Cheats/ folder.
With the ISO file safely transferred to his internal storage, Alex opened PPSSPP. He navigated to the folder, his heart beating a little faster. He tapped the icon of Ryu preparing a punch. street fighter 4 download better for android ppsspp