If you're lucky to have one of the supported devices, go ahead and check it out. I tried to install the N95 package (unpacked just like the first access method, of course, as they used the same sort of "protection" again) on my N93, but couldn't start it. However, it might work if I remove the first access package first. We'll see, right now I feel more like going to bed.
It's interesting to note that the N-Gage team keep mocking the poor 3rd party developers by using an excessive set of capabilities for something as simple as the installer application. Alienating 3rd party developers seems to be very popular in the Symbian camp these days. And "security" is obviously just a buzzword to them.