I also like it a lot when people who don't like Sonic (anymore) post their views on Sonic. We tend to talk about the same things over and over, and I appreciate that Sonic is discussed under a different light. So anyway, @Laura has it right when she talks about how moving the camera to the left doesn't help as much as the proponents say it should, because vertical movement is very important to Sonic, and also because you'll go left a lot (especially true in Sonic 3 & Knuckles and Sonic CD). This may also change quickly, and having the camera move as fast as the direction of the movement changes is very jarring. So really, I don't see how there's a visibility issue. You don't say there's a visibility issue in on-rails games that demand fast reaction times. It's something else altogether; something that derives from not only the camera, but many other factors that are intertwined. I know this is elusive, but it's simply that there isn't a simple fix to Sonic as a whole -- and, once again, proposing as much can only come from applying external parameters of what a game should be to Sonic. (Also there's an article I really like about the camera in Sonic, but which I don't think I'll be able to find, that talks about how it works differently when Sonic is on the ground vs. mid-air, and how that interferes with the gameplay. And it really sold me on the idea that, at least at the time, there was no other way it could behave.) That's not to say there isn't an issue. It's just not a question of whether enemies are visible when they should or not. Or, at least, not only that.