Perseus,
Your slower cpu and hard drive will hold you back a bit. Consider hard drive, cpu, video card, system bus, processor caches, and memory.
Still, it's a very nice looking game and innovative in a few ways. Probably the biggest highlight is when you get to storm the beach at Normandy. Nasty!
My quibble is closer to the end where, if you are seen and they trip the alarm, baddies come after you, with unlimited backups until the alarm is off. Unlimited? No fair!
Also, unless you have amazing reflexes (or no life) think twice about playing in the hardest mode (hard, I think, easy, medium, hard).
It's taken me months and I'm still not quite finished.
Doug
EDIT: I just remembered. . . It runs quite a bit faster in OS 9. I can max out almost everything in OS 9.