In order to play this, or any other zcode game file (ends with a .z5 extension), you need a Zcode interpreter. There are a zillion of them out there for multiple platforms. Below are links to ones I'm aware of. Your mileage may vary. I endorse nothing. Nothing! However, I have used Zoom on the Mac and Kronos on my Palm, and I like both. (The Palm interpreters seem to all require expansion cards, as far as I can tell.)
Mac OS X Interpreters
Zoom
Windows Interpreter
Frotz
Palm Interpreter
Kronos
Pocket PC Interpreter
Pocket Frotz
IF Resource (links to games, interpreters, etc.)
Interactive Fiction Archive
Last updated: 10 June 2005