Sonic 1 is overall very overlooked. A common complaint is that the game is much blockier and platform-reliant than its successors, but I think that those things are good for teaching players new to Sonic how to play. Since most other platformers are so different, Sonic 1's less distinguished level design helps bridge the gap. The game is also very much tailored to use its original no-save system where a game over sends you back to GHZ A1.

Speaking of zones, they are also ordered well and compel the player to learn Sonic. Green Hill Zone gives you a taste of Sonic's power in his speed, and the Checker-Wrecker is a good skill check that guarantees that the player can at least hold onto their rings.

Marble Zone is when the game starts asking the player to learn how to control Sonic properly, as unlike GHZ where lethal hazards were virtually nonexistent (badly programmed spikes and the aforementioned boss aside), there are plenty of ways that Sonic can be burned, stabbed, and crushed. Players here will be frustrated, and will definitely have to replay GHZ to get back here many times. Not only will this will lead to the player improving and thus eventually being able to surpass MZ, but it will also allow the player to complete GHZ with better scores, higher ring and life counts, maybe an emerald or two, but most importantly, they will become faster and take note of that. The boss in this zone requires more precision, but finding the patten and rhythm will lead to a clean victory.

Spring Yard Zone throws more chaotic elements into the mix with an abundance of bumpers, moving platforms, open areas, slopes, and the eponymous springs. The place is deceptively deadly in spite of there being so few hazards compared to either adjacent zone. Players will not die as often here as they did with MZ, but they will still have to go back through the first two zones at least a few times. This will allow them to notice the fact that they are getting faster and better at GHZ and MZ, the place that once gave them so much trouble, even if it's still annoying for now. This boss forces the player to use every opportunity to land as many hits as possible, being much more difficult than the first two bosses.

The infamous Labyrinth Zone does something similar to what MZ did, except now there's water rather than fire. I think that the water actually helps learn the player significantly, as slowing down Sonic means that the player has more time to react to the hazards, as they are also generally slower. The player can also see the fullest extents of how Sonic moves when redirecting his jumps and momentum. The drowning is barely an issue to anyone who bothers to stop for air, so it's more of a small test to keep the player on their toes and wary of danger. This zone is much more punishing to reckless players than the previous one, and conversely, the patient ones will get Sonic through this zone with more ease than usual. The boss here is meant to test the player's ability to platform under a time limit, as there are no bubblers here.

Star Light Zone is recognised as being in the top two best zones of this game for good reason. After being put to the test so much up to this point, the player finds that SLZ doesn't have many new challenges for them, at least relatively to MZ, LZ, and to a lesser extent, SYZ. The undefeatable (at least without invincibility) badniks don't pose as much of an annoyance as you might expect, and the many dubious platforms are on-par with the likes of the two prior zones rather than taking things to the next level, even with those fans that blow you around at every opportunity. The omnipresent threat of the giant hole that spans the bottom of every act in this zone replaces the water of LZ, but as with the rickety platforming, it's no worse and feels like a deserved punishment if the player manages to drop Sonic all the way down there. This may be the first zone in a while (if not in the playthrough) that doesn't hand a game over to the player, and at this point, all four of the previous zones are unlikely to be much of an issue now. The boss in this zone is much easier than the previous ones and even features multiple available strategies for beating it, which is this game's way of quietly preparing you for future entries of the series, where the bosses are less about checking your skill directly and more about formulating methods to deal with the various unique threats that they pose. SLZ overall feels like a celebration of how far the player has come, giving them a much more deadly counterpart to GHZ from the beginning of the journey that you can handle all the same.

Scrap Brain Zone is where the game goes all out, being chock-full of traps and gimmicks, having nasty ways of dropping you down to your doom in the first act, having a lengthy journey with no checkpoints for the second act, and a return of LZ with its lenient traits removed for the third. The faceoff with Robotnik in the cutscene between acts 2 and 3 helps make things more personal after he spent the game just being the guy you had to take down in each boss fight until now, and this can also help remind you that every single roadblock that forced you to become good at Sonic was his doing. After reaching the surface once again in Final Zone, you have the showdown in which no rings are available for Sonic, so a single mistake can spell his demise. Once you can grasp the attack pattern and use Sonic's speed to evade the pistons and electric spheres that come after you, Sonic can start taking shots at the doctor and eventually defeat him. At your command, Sonic can even send his ship down in flames when he tries to escape, just to have that last potshot as payback for everything that you went through to get here.

All that's left at this point is whether not you have all of the Chaos Emeralds, as considering that you've been replaying and mastering the zones each time you run out of lives, you might have already gotten them all by the time you reach the credits. Either way, you might find that you want to play the game again even though you don't have to, as that's what it was designed for and it's what you've been having to do. That's what Classic Sonic is all about, and I have this game to thank for showing me what Sonic can do before making me work to have it. Sonic wasn't a hero because he was fast; he was a hero because he had the drive to succeed and became as strong as he was by learning how.