City Pearl gain starts out at 1P/35Lv, until Lv70, when it becomes 1P/10Lv, then 1P/5Lv at Lv140, 1P/4Lv at Lv210, 1P/3Lv at Lv280, 1P/2.5Lv at Lv350, 4.5P/10Lv at Lv420, 5.5P/10Lv at Lv490, 6P/10Lv at Lv560, 6.5P/10Lv at Lv630, 7P/10Lv at Lv700, and continues to increase incrementally every 70 levels.
Haven't checked Beach or Countryside yet for Glitch or Pearl gain rates. Countryside needs to be reset first, so I'm saving it for last. Probably won't bother with Beach, since it supposedly doesn't count towards Pearl gain at all.
The Spiral Glitch doesn't always kick in at the City, unlike the Campus, where's it's always useless. Sometimes the Spiral works, sometimes it doesn't. It must be difficult to program so many games at once. Hope Changer is getting enough sleep.