Nintendo demoed two upcoming DS dungeon crawlers -- Pokemon Mystery Dungeon: Explorers of Time and Pokemon Mystery Dungeon: Explorers of Darkness -- at its recent press event in San Francisco. The two games, like the proper Pokemon games, feature the same content, but there's a different mix of Pokemon in each. The games are the sequel to 2006's Pokemon Mystery Dungeon Red and Blue, which appeared on the Game Boy Advance and DS respectively. To keep things simple, the two sequels stick to the DS and build on the basic dungeon hack-and-slash of their predecessors. GameSpot had the chance to try out work-in-progress versions of the games to see how they're shaping up.