Because if you simply convert it to EBOOT.PBP then it wont launch and will give you the black screen. Right now I am trying to figure out how to compile the game from source to make it work on a PSP. Hope that cleared up some questions=]
Hey there, sorry for the delay on the answer. I don't think it might work because the PSP emulator is prepared to run games made with PsyQ. Generally, older PS1 emulators implement memory mapping "the wrong way", because PsyQ SDK also access memory-mapped devices "the wrong way". PSn00bSDK, which is what I use, does it "the right way" but this also means that most emulators do not implement these aspects properly and that has never been an issue for most games. I noticed for example that you can't run this game with proper audio on Emulator.js using the PCSX core because it uses an older version of this emulator (or at least, it used to); so unless someone is actively updating PSP's emulator, you'll be stuck with a black screen.
Unfortunately, this is not a matter of simply trying to recompile the game from source. One could argue that a port from PSn00bSDK to PsyQ could help, but this is too much handiwork and does not solve the actual problem.