I guess I should explain the whole missing Act 2 thing, since I have seen confusion about this come up a few times. Technically, the Hubs are the Act 2's in the actual disassembly code. At first, the hub used the Act 2 Title Card, but having no Act label seemed more appropriate, so I removed it. However, if you have found any of the secret unlockable acts yet, you'll notice that I re-used the Act 2 title card there. I guess I intentionally left it that way as sort of an underhanded way to induce exploration in the hub. So, to access the secret acts, you must fully restore both acts and the hub (for the hub restore to actually save, you have to leave and come back to it either through an act or another zone), then look around the hub and find the now activated Giant Ring. Since it seems like no one has found any of them, here are the locations: Spoiler Green Hill - In the underground area to the right where the Music Monitor is. Marble - In the underground area all the way to the right, through the secret tunnel (past the C Monitor room). Spring Yard - At the end of the bottom path to the right of the Act 3 entrance, in the same room as the C monitor.