A chaotic, humorous 2D side-scroller developed by Nippon Ichi Software that matches the vibrant, unforgiving difficulty of Castle Crashers.

: The game was developed by The Behemoth for Xbox 360 , PlayStation 3 , PC (Steam) , Xbox One , PS4 , and Nintendo Switch .

Any files claiming to be an "exclusive" PSP ISO for Castle Crashers are typically fan-made homebrew projects, custom themes, or potentially malicious files. The Reality of Castle Crashers on PSP

If you want to find more games to play on your handheld, let me know: What specific genre(e.g., RPG, fighting, platformer)