Because the PS Vita lacks the L2/R2 and L3/R3 buttons found on a DualShock controller, Sanzaru Games utilized the handheld's unique hardware for contextual actions:
The Vita port, developed by Sanzaru Games, was an ambitious feat. It brought the sweeping scope of Ancient Greece to a 5-inch screen. The controls translated well, utilizing the Vita’s physical buttons to mimic the DualShock experience, which was superior to the touch-only controls found in other Vita ports (like the infamous Borderlands 2 port). god of war collection ps vita rom