Be cautious of sites offering "high-compressed" 300MB ISOs of the full MK9 game, as these are often non-functional or harmful to your device.
If you want the authentic Mortal Kombat 9 gameplay—complete with the and the 2D fighting plane—you have better options than searching for a non-existent PSP ISO: mortal kombat 9 psp iso download top
Some mods change the health bars and menus to mimic the 2011 reboot's aesthetic. Be cautious of sites offering "high-compressed" 300MB ISOs