The number "171" often included in these search queries is a significant tell. The original version of Castle Crashers had a file size of approximately 171 MB (sometimes cited as roughly 158-180 MB depending on updates and region).
Build 171 is a tech demo , not a full game. You will not beat the Final Boss on a PSP 1000. castle crashers psp iso 171 top
To put it bluntly: The file does not exist as advertised. What you will find are either broken fakes, malware, or outdated homebrew experiments that crash on level one. The number "171" often included in these search
If you owned a PS3 with Castle Crashers and a PSP, you could technically use "Remote Play" on a very limited set of games. Castle Crashers did support Remote Play. So, that avenue is closed. You will not beat the Final Boss on a PSP 1000
Since no official port exists, what are people actually downloading? The few files labeled "Castle Crashers PSP" floating around the internet fall into one of four categories: