Thought I'd write a post about the concept maps. Did some thinking and I think you could support Sonic 2's development as in line with the time zones concept or that Sonic Team dropped it very soon in development. In sum...we don't know. Lol! Going off the time concept maps, it seems like you would go through the zones in order of the time zones. So Now 1-Past-Now 2-Future. The maps even have arrows in the order of which the player would go through the zones on the map. It's a clear indication that the player would play through all zones of a time period to reach warp zones to reach the next time zone. It seems entirely linear to me and not at all like Sonic CD. So for all intents and purposes we can read the below list as the rough level order of the original concept: Now 1: Emerald Hill, Wood Zone, Sand Shower, Metropolis, Ocean Wind, Warp Zone Past: Tropical Plant Zone, Hill Top Zone, Blue Lake Zone, Olympus, Rock World Zone, Warp Zone It's unclear how Tropical Summer fits in. Now 2: Because the arrows aren't on the map the order is unclear. But they have Dust Hill, Oil Ocean, Rock World Zone Future: Chemical Plant Zone, Casino Night Zone, Genocide City Zone. Now first of all, that's 17/18 zones. Lol! Pretty sure Sonic Team knew not long into development that number was far too ambitious. Sonic 1 only had six zones. Sonic 2 managed 11 zones and that's an impressive number. Nick Arcade has Emerald Hill, Hill Top, Chemical Plant, Hidden Palace. On the order of the zones on the concept map that's Levels 1, 7, 15. It doesn't make sense to me to make the levels out of order. It's also not how Sonic 1 was designed. In that game the levels were clearly developed in order. Green Hill and Spring Yard are more developed than Labyrinth and Scrap Brain in the prototype. Perhaps Sonic Team started Emerald Hill and Hill Top in tandem since they were time zone counterparts. But then during the development of those two zones quickly dropped the entire time zone concept for being too ambitious. Maybe they wanted to design a Now, Past, and Future Zone in development to get a feel for things? Who knows! It's also worth noting that even at this early stage the game doesn't seem to make much sense for difficulty scaling if they were going along the lines of the original time map concept. Chemical Plant is at the end of the game but is an easier stage than Hill Top which is in the early-mid game. Maybe Chemical Plant was easier like Star Light before moving to the originally more difficult Casino Night and Genocide City ala Scrap Brain? Maybe they had already changed their mind about time travel. Who knows! Sonic Team never had a particularly level headed approach to difficulty scaling. In the Simon Wai prototype it becomes a bit more logical. We have Aquatic Ruin, Chemical Plant, Hill Top, Emerald Hill, Wood Zone, Metropolis, Hidden Palace, Oil Ocean, Mystic Cave, Casino Night, Genocide City, Death Egg. Based upon the concept map, that's Level 1, 2, 4, 7, 9 (perhaps if Olympus is Aquatic Ruin), 13, 14, 15, 16, 17. Now it's possible that Sonic Team wanted to keep the original time travel concept but decided to cut down on the amount of levels for each time period. The prototype does have a generally even level representation for each time period: Now 1 has 3/5, Past has 2/3, Now 2 has 2/5, Future has 3/3 in development. However, it's also possible that Sonic Team simply dropped the time travel concept entirely and just stuck to the level themes which they had created in early development. It is notable that in Simon Wai the Zone Order has changed significantly and completely conflicts with the order of the Time Zone maps. But then the level order might not actually mean anything and might just have been done for the purposes of the prototype. Who knows! So yeah, that was a long post about how we don't really know anything. So this whole thing has pretty much been a waste of time.