Single Status Update
You know, I really appreciate how the later stages in Mania are very well connected narratively. There are oil tankers being shipped between Mirage Saloon and Oil Ocean, the oil is shipped to Lava Reef on Angel Island where Eggman has started a mining facility and has managed to tether Little Planet, and Lava Reef is actually connected straight to Metallic Madness, which is the construction site of Titanic Monarch. You're actually progressing through all the parts of Eggman's plan in the second half of Mania (Hydrocity aside, which still doesn't seem to make any sense).
The first half of the game is a little less clear. You can infer some sort of story relating to Studiopolis and Press Garden all being in aid of pro-Eggman/anti-Sonic propaganda, and Flying Battery operating in the background to transport or recycle materials, but the story doesn't really pick up until you find yourself in Stardust Speedway.
Green Hill - stopping Sonic in progress
Chemical Plant - use Puyo Puyo to make sticky substances for Titanic Monarch
Studiopolis - TV advertising
Flying Battery - Studiopolis to Press Garden (and vice versa) transport
Press Garden - propaganda printing papers
Stardust Speedway - speeded-up construction of Eggman statue (it´s more completed than the CD´s rendition in Present timeline)
Hydrocity - material and techniques to build Titanic Monarch
Mirage Saloon - chain of bars + train track used for oil to be transported to Oil Ocean
Oil Ocean - refineries to produce oil for use in Lava Reef´s mining and transporting activities
Lava Reef - Eggman´s mining factory (another material source) with rockets used for transport to Little Planet, which is tethered to the volcano.
Metallic Madness - Eggman´s machinery production to use in Titanic Monarch
Titanic Monarch - the final product
Makes perfect sense.