Moonlight is an open-source implementation of NVIDIA's GameStream protocol (now supported via the open-source Sunshine host application for all GPUs).
This is the best way to play. You can run GTA IV at 60 frames per second at the Vita’s native resolution (960x544) with maximum graphic settings. Method 2: PlayStation 3 Remote Play gta iv ps vita
To understand why GTA IV never officially landed on the PS Vita, we have to look at the massive technical gulf between the console's architecture and the game's demanding engine. The RAGE Engine Demands Method 2: PlayStation 3 Remote Play To understand
If you own a PlayStation 4, the most seamless way to play GTA IV on the PS Vita is via official Remote Play. A hypothetical “re4” project — recreating GTA IV’s
The immense success of the re3 and reVC projects (reverse-engineered GTA III and Vice City) has demonstrated that community-driven engine reimplementations are possible. A hypothetical “re4” project — recreating GTA IV’s engine — could theoretically be ported to Vita, though the technical challenges would be monumental given GTA IV’s vastly more complex engine and the legal risks involved.
