After playing for a while, the game 'freezes' (though the music does not).

It doesn't sound like something that can happen - the graphics card dying..... It just doesn't sound possible.. the only thing I can think of, if that were the case, would be if you removed the heatsink while modchipping your machine, and it gets too hot... if that's the case, you may want to get some thermal paste and put some inbetween the graphics chipset and heatsink.... It sounds to me like the game may be a dud... or perhaps, have you checked the FAN? If for some reason it doesn't spin, it could be overheating...? In my opinion, I don't think it's possible for a graphics card to die... overheat, yes.. but die through depreciation is a new one.. it has no fan, so it is pretty much near a 0.0000001% chance of that actually happening.... The fact that the disc is still spinning would imply that the game is still reading... so, perhaps, the part of your VGA Output on the GameCube could have issues regarding OUTPUT OF VIDEO... loose wire that rattles perhaps, that needs refitting somewhere..? It honestly sounds like OVERHEATING FREEZING to me... CHECK THE THERMAL PASTE STORY.. AND THE FAN STORY... It's a classic case of overheating in my opinion.. I've seen it happen to my computer.. All I have to do is leave my case panel off, as it gets hot , and the exact same symptoms show up... And in the worst case, it could be an issue of unplugging and replugging cables. Hope that helps..