OpenGL or Vulkan (Vulkan is usually faster on newer Androids). Frameskipping: Set to 1 or "Auto."
A "highly compressed" file might actually be a valid PC repack of ETS2 (e.g., from FitGirl or Dodi). But you cannot load a .rar file containing PC .exe files into the PPSSPP emulator. PPSSPP only reads .iso or .cso (PSP disk image formats). If you drop a PC installer into PPSSPP, nothing will happen. euro truck simulator 2 ppsspp highly compressed work
For a "highly compressed" and smooth experience, these native Android games are developed specifically for mobile hardware and offer better graphics than any PSP emulator could: OpenGL or Vulkan (Vulkan is usually faster on