Dungeon is considered to be another difficult course despite its thematic tribute to the Dig Dug franchise. Like Hexagon, this will have a 6-minute timer on Pro difficulty.
Given the cramped layout and lack of Power Pellets in Phase 1, it's easy to think about being behind in Phase 1, with a score lower than 2.5 million around the 3 minute marker. However, Phase 2 has healthy amounts of ghosts and a hefty amount of points from Pac-dots, given that there are no deaths. Even with a death in Phase 2, there should be no problem finishing out in the end-game.
On the first Power Pellet, trains are limited to 30 ghosts. Keep that in mind when passing through the 4 clusters of ghosts. Odds are, the 4th cluster is better spent eating them than passing through.