UmJammer Lammy 1/22/1999 Build (PSX)

It turns out this is just the final game, dated 7/1/1999. There's nothing different about it at all other than some stuff in the executable. Here it is regardless, though.
https://mega.nz/#!bcBlgI7J!FThVqGFoUbc6oNCoHbVqKMzbUf02UxzuPqVKlp_Y7qI

 

actually, it's dated 1/7/1999

 

Wait a minute, i'm completely wrong.
it's dated 7/1/1999.

This is just the final game. The only differences seem to be in the executable.

 

The build you posted is dated July 1, 1999, based on the date of the executable.
The final game was compiled on July 15, 1999.
The game was released August 17, 1999 in North America.
This version was built after being localized, so it's not actually a prototype to the game.
Still interesting, however.