Firstly, it gets the basics right. The reason it's aged so well is that it's smooth, so there's no hint of the tech being too old. Also, the 2D art is very stylised, even hinting at flat-shaded 3D in the trees (pictured) and bonus stages - futuristic for the time, now fondly remembered by retro enthusiasts. 2D doesn't age like 3D does and everything here is chunky and solid enough to remain convincing, even today.
Also, crucially, there's just Sonic. And he doesn't talk. He's just a blue hedgehog who can run faster than the speed of sound and so he sprints around loops, crosses spiked logs and frees innocent animals from their metallic prisons. It's good vs evil with nothing else tacked on. It doesn't need anything else.
Robotnik was a great villain, appearing in a brilliantly ridiculous contraption at the end of each level.
The music is rightly famous and has been remixed and performed on YouTube countless times. The core sound effects here are still used in Sonic games today and the secret rooms, level selects and hidden routes are ingrained into the consciousness of an army of 20-somethings. Up, down, left, right, A+Start together... it's the mantra for an entire generation (or at least the non-Nintendo-owning half of it).
The game is difficult but fair, throwaway fun or obsession-triggering. It's also fast if you want it to be, or a slow, methodical platform challenge. Do you want to collect every ring? Search out every extra life or item box? Collect all six Chaos Emeralds from the trippy special stages? It's your choice.
Above: Some zones were slower with careful jumping needed - something modern Sonic games have forgotten about entirely
Like all the best games (like Halo 3, CoD4, Skate...), Sonic The Hedgehog provides you with a constant, solid playground in which to have fun and then lets you get on with it. And fun is definitely something you'll be having when you play it. Yes, even today - and that's why it scores an 'incredible'ten rating from us. It's still worth your money. Maybe not £40 like new titles, but for the price of a Virtual Console or XBLA download, you simply cannot go wrong.
We talked aboutPortalbeing the perfect videogame, but this has to be right up there with it. It's utterly essential for anyone who considers himself/herself a fan of videogames.