Sonic 1 Secret Stuff
Although Sonic 2 is the most popular game to look for secret stuff, Sonic 1 has some hidden secrets as well.
Sparkling Zone?!?!? As you can see, this is a really early version of Spring Yard, and the background looks very different from any other background I've seen.
Speaking of Spring Yard, why can you place a Caterkiller there?
And why is there an unreachable area as seen here?
Here's a REALLY puzzling picture of Green Hill Zone. The graphics are dark in color, and the background is really different, but most importantly, what the heck is that sign doing there? You be the judge...
Here's another mystery to think about: Scrap Brain Zone
You can see in the above picture this is an early version of SBZ called Clock (W)ork Zone. The background is completely different from the final Scrap Brain, and the graphics are brighter.
Another Scrap Brain oddity: The picture below shows a location in the level you can't get to without debug. And the pipe below takes you down instead of up!
A final mystery to explore in the game is the Special Stage. If you look in the Sonic 1 manual, you'll see a picture of a 1-Up Icon in the special stage, but that icon cannot be seen anywhere in any special stage! But you can get it in debug mode as seen below. There's also a few Chaos Emeralds as well as...a "Zone 3" icon???
SEGA probably took the 1-Up out of the game because players would get a whole slew of lives if they hit it many times, and they couldn't do anything about it. That Zone 3 thing puzzles me though...was there supposed to be something where if you had a certain number of rings and hit that, you would warp to another level? I guess we'll never know...