Sounds to me like you have a Mac with a PowerPC processor. If that's the case, then the PC version of Tron 2.0 will not work for you. Getting the PC version to work pretty much requires an Intel processor. Rosetta is too slow to run the game well. And I don't think any other form of emulator would be fast enough, either.
You'd have to stick with the MacPlay version. Which, of course, will not work on OSX 10.6.
The MacPlay version was was not that well coded, in the sense that it used emulation techniques that simply are simply no longer compatible with Leopard and Snow Leopard.
But if I'm misinterpreting you, and you do have an Intel processor, then there are several solutions to getting the PC version of the game to run on OSX 10.6. I highlighted the free one, CXZ, on my site. But there are several other solutions: like Bootcamp, Parallels, VMWare Fusion, and Crossover.
In that case, keep an eye on Amazon.com. Eventually someone will sell a copy of Tron 2.0 PC who doesn't want to gouge people.
EDIT: For some reason, I got it backwards when it comes to Rosetta. It translates PowerPC instructions to Intel, and not vice-versa. Duh. So you do have an Intel processor, then.