If you get the not loading a sound file error
Inside the game's folder (called startup in waudby's download) open the folder called sounds, in there open the folder called battle and change "Battle! Wild Pokémon.mp3" to "Battle! Wild Pokemon.mp3" then, go back into the game's folder, open the folder called scripts, open the file called Vars.js with a text editor, look for "Battle! Wild Pokémon.mp3" and change it to "Battle! Wild Pokemon.mp3".
If you're on a mac
As well as waudby's game download, also get: spheredev.org/~rhuan/sphere.zip and spheredev.org/~rhuan/frameworks.zip
Put the contents of frameworks.zip in ~/library/frameworks, drop the game folder (startup) from waudby's download into the folder produced by opening sphere.zip, then run SphereEngine.app, if it doesn't work, you may need to run Config.app first and select a video driver, I recommend sdl_gl it's faster than sdl32. You may also get the music file error mentioned above, if so, follow the fix I give above.
(I'm the mac sphere developer BTW, so if you have any mac sphere related problems, ask me)