In Episode I, there's the rotating mazes, which now play just like Cameltry (you control the maze's rotation and there's a time limit). This becomes a non-issue if the player unlocks Super Sonic. Thankfully, Sonic carries a torch throughout the entire act. Blackout Basement: In Episode I, Lost Labyrinth Zone Act 2 has some sections without much light.Bears Are Bad News: White Park Zone features a gigantic polar-bear type badnik with large claws that takes three hits to go down instead of the usual one.Bash Brothers: Episode II sees the return of "Sonic & Tails" mode with 2-player co-op (offline and online), complete with at least one new combination attack and Tails being able to carry Sonic.Bait-and-Switch Boss: The first boss of Episode II does this by tricking the player into thinking they are going to fight another nostalgia boss, but then Eggman goes to the real boss machine immediately afterward.Background Boss: The Sylvania Castle and Oil Desert bosses.Bad Future: As seen in Episode Metal, Metal Sonic apparently hails from Stardust Speedway's Bad Future, which looks extremely familiar to a previous version.Auto-Scrolling Level: Sky Fortress Zone Act 1.
Ash Face: Eggman gets that after yet another unsuccessful battle.Art Evolution: Episode II receives a very noticeable jump in the graphics department compared to Episode I, as the zones have a more detailed and three-dimensional appearance to them and the models lack the cel-shaded look they had in Episode I.Arc Welding: A Sega rep confirmed that Episode I does this to Sonic CD, as it wasn't considered to be significantly tied in any way to the numerical Genesis trilogy.Anti-Frustration Features: The iOS port of Episode II Special Stages has Sonic's horizontal movement slightly slowed down although this sounds like hell, they removed the traps.
The former has sections of moving track, while both have sections of missing track.
It's an Episodic Game, with only two episodes released. Sonic the Hedgehog 4 is a side-scrolling platformer developed by Dimps that is a throwback to Sonic's roots on the Sega Genesis, as well as being a response to the series' Polygon Ceiling-related criticism. The ones where the franchise went back to 2D, but was still 3D!