Originally Posted by Maxxa
The only issue that may arise with old cartridges are the batteries inside the ones that store save data may need replacing, aside from that if they were kept out of a swamp they will be fine after 20 years. I have batteries in my games that still hold saves after this long.
Actually they may still work after that. I've had a Wii, Game Boy, SNES, and N64 along with games for all of the above submerged in sump pump backup water in my parents basement. Some multiple times. The only one that "broke" was the Wii and the problem was it wouldn't eject the disk which I fixed by disassembling and reassembling the mechanism (no idea what the problem actually was).
It always cracks me up when I see Xbox 360's fail and what not because of all the stuff the Nintendo products I own have gone through. I don't think the DS is as bullet proof as the Game Boys though. I've done so many horrible things to those with out any consequences.