Anyway, it runs fine (albeit slowly) on a 2.5 PSP, should run on a 2.0/2.01 - have no idea about a 1.5 though (don't go upgrading for this one guys...).
A zip file is attached containing a HTML doc, there's more detailed comments inside it on how to play/install/etc. Will put up a screen grab too.
The slow frame rate really lets the game down, but let me know if you get 5min enjoyment out of it! If anyone knows how to get it running any quicker - make a suggestion.
And if anyones maintaining those PSP portals, feel free to add this in (released under LGPL).