Sony developers. By January 2011, the game was running on the Vita hardware and the team focused on polishing the graphics and gameplay. The pressure to create a first-party Vita title in time for the platform's year of release put a large burden on the development team. A moment Toyama remembered later was when the Vita was publicly revealed, which saw Gravity Rush announced as part of the platform's launch line-up; due to the game suffering from unresolved frame rate problems, Toyama felt anxious about completing the game. Design Toyama's greatest inspiration on the gameplay of Gravity Rush was Crackdown, influencing the upgrade system and open world. During early stages, the team contemplated giving players safe areas within which the gravity manipulation would play out similar to a puzzle, but test player feedback led to the gravity-based navigation being applied to an open world. The team discarded the concept of fall damage. Toyama had the team watch the film Hancock as a reference for Kat's "sluggish" movement through the air. The lack of a targeting reticle or automated aiming was included partially to focus player attention on the Vita's gyroscope functions and to prevent the game from being too easy. The touchscreen controls were intended to play a larger role in combat, but Toyama found the result more difficult to control and so restricted it to dodging. The map design, which used a simple 2D design, was meant to ease navigation for players exploring the city from above using Kat's powers. The most difficult gameplay move for the team was the Gravity Slide. The decision to have an open world town caused the gravity manipulation mechanic to become the basis of nearly all gameplay elements. During early testing, the team created small test areas such as enclosed rooms and tunnels, first determining what cues to give players about which was up and down when manipulating gravity. To this end, they included flying vehicles, distinct architectural styles with clear tops and bottoms, and other elements such as the movements of people and how Kat's clothing behaves. A major issue with the gameplay was ensuring the environments had proper collision detection; while most games had multiple inaccessible areas which lacked collision detection, the gravity mechanic meant that the player could navigate a larger number of surfaces in the game, necessitating increased focus on ensuring collision detection for all surfaces worked as intended.