I recently encountered a very strange little "softlock" of sorts, which essentially traps the player and forces them to kill themselves to restart in Metropolis Zone act 2. It centers around this area here: Note how the signpost is very, very close to the lower level segment on the x axis. In my hack, in all variations of MTZ act 2 (including the untouched vanilla one), running from the left and jumping straight into the wall triggered the signpost art to load, corrupted the art of the lower spring, and locked the camera, forcing you to go to right. When your underneath the signpost in the rotating platforms segment, this traps you on the platforms, and the only way to leave is to die in the lava or time out, then avoid jumping straight into the wall again. In vanilla sonic 2, this doesn't occur, but will if you use debug mode to clip ever so slightly into the wall. That wall is literally right on top of where the game checks for the signpost to load and the camera to lock. So if your making a hack that preserves the original level layouts but increases the players speed and/or disables the midair speed cap, you might want to watch out for this one. Fixing it is easy; just go to "LevelSize:", and change MTZ2s' x end value from "$1E80" to "$1EA0". It pushes the boundary for the level to load far enough away from the wall to avoid the problem, but also doesn't push it back too much to be noticeable. EDIT: On another note, it might be related to the CD styled extended camera too. Either way, worth knowing.