Download it for free on the App Store or Google Play.
If you want a high-quality, smooth running game similar to Subway Surfers on your PSP, it is highly recommended to play the official games that inspired the genre. These run perfectly on PPSSPP. subway surfers psp iso upd download link
If the file is an EBOOT, place it in PSP/GAME/SubwaySurfers/ . Official Platforms for Subway Surfers Download it for free on the App Store or Google Play
However, many gamers look for this because of custom homebrew ports or similar games. Here is the solid guide on how to get the closest experience on your PSP. subway surfers psp iso upd download link
If you want to play Subway Surfers or similar games on Sony handhelds, consider these options: Download Subway Surfers 3.61.1 for Android | Uptodown.com