Once a smart, hip place to hang out, Mobius has suffered immensely at the puffy hands of Robotnik. His redevelopment plan for many of its zones (all completed without planning permission, naturally) left it disfigured and dangerously unsafe. The result was to turn one of the cosmoverse's coolest spots into a total no-go area - unless you're the sort of hardy, outdoor type who relishes the challenge of rock-hopping lava pools, examining deviant flora and fauna whilst dodging giant spikes. Robotnik let his diseased imagination run riot, and turned many zones into hell holes worse than a timeshare on a Grade One penal planet.
In Sonic 1 Robotnik and Sonic battled it out in six of Mobius's better-known spots, beginning with what was originally their home patch, the Green Hill Zone. Robotnik's early efforts now seem half-hearted by his usual despicable standards, extending only to boring through the hillsides weakening many cliff edges so they crumbled away without warning; or installing rotating spiked tree trunks. Subsequently his work on areas like the Marble Zone, to which he imported a job lot of dungeon equipment, and the Star Light Zone, to which he brought his new-found love of pollution and industrialized blight, demonstrated that Robotnik was a force to be reckoned with.
Revenge is DiscreetEdit
After Sonic foiled Robotnik's warped masterplan to control Mobius and destroy him, the planet returned to relative normality. The zones were reconstructed and the minefield of traps and hazards was cleared. Sonic was reunited with his friends and rapidly returned to his old habits, nosing around, messing about and playing practical jokes. He even found a new friend in Tails. Everyone thought the ordeal was over, but Robotnik was still at large.
Things, however, did go quiet for a while, but it was only the calm before the storm. Everyone, Sonic included, was lulled into a false sense of security. Robotnik had merely gone to ground to plot his revenge. Working behind the scenes with his vast fortune, he began infiltrating the infrastructure of Mobius, gaining control of entire cities and factories for his own ends.
Then the disappearances began. At first there were so few that no one noticed but they spread. Soon more and more familiar faces had gone mysteriously missing. Then came the rumours, fuelled by Robotnik's propaganda apparatus - that a deadly virus was loose, animals were being sucked into space by a giant tractor beam and there had been an outbreak of spontaneous molecular combustions. The truth was far worse. Robotnik had begun work on his most devious creation yet, the Death Egg, a powerful device capable of destruction of apocalyptic proportions. He was abducting vast numbers of animals to work on its construction in an underground factory. Robot hit squads were sent out at night to snatch animals who were then drugged and transported to his factory. There neurological implants were inserted in their brains which turned them into automatons.
He had also not forgotten the damage Sonic had inflicted on his plans last time, so he had constructed another set of zones which he placed between himself and the superfast hedgehog. Never one to admit he was wrong, he gave many of them similar themes to the zones he had constructed in Sonic 1. As an extra incentive to lure Sonic into his clutches he sealed many of the supersonic hedgehog's friends in prison eggs which he cleverly situated at the end of each zone. The demented prof also customised the Egg-O-Matic, adding a new set of weapons. Monitoring his progress through the zones he was now able to swoop into the attack the moment Sonic looked like rescuing his pals.
As ever, Mobius's only hope of a return to normal service lay with Sonic. It's pretty daunting to realise that the future of an entire world - and that of all your friends - lies with you (imagine being asked to save the rainforests before breakfast) but Sonic wasn't the sort to be phased by such minor considerations. And he sill had the rings to provide some protection!
When Robotnik's (or Kintobor's, if we're being precise with our timescale) ROCC blew its top, one of the side-effects of the eruption was to launch more gold rings into the atmosphere than an explosion in a jeweller's shop. Even a scientific slaphead like Robotnik will concede that what goes up must come down, and down they came - all over Mobius. It didn't take long for Sonic to discover that they offered some protection from the downright antisocial traps that Robotnik had devised to try and bring about his untimely end.
Back when Kintobor was still a sane, genial scientist with the noble plan of ridding Mobius of evil ("that pathetic creep of an inventor do-gooder" as Robotnik now refers to him) he had installed a netweork of PCs all over Mobius in the hope that like-minded citizens could enter information as to the whereabouts of the Gray Emerald.
Up to the tragic moment when the ROCC went into meltdown and Kintobor's sanity logged off permanently, it had to be said that the PCs hadn't been an extraordinary success. Perhaps it was asking too much, but all that had been entered on the hundreds of machines scattered about the place, was a stream of abusive messages, offensive poetry and a strongly-worded letter to the Mobian Daily Herald. Others thought they were bank creditpoints, local information guides or quiz machines. However after the rings came down to earth Sonic discovered that the PCs had altered their make-up, too. By an intricate molecular process far too complex to discuss here without going into immense detail, the PCs had absorbed some of the rings, while others had gained even more useful powers offering shields, power-ups for his trainers and invincibility boosts when he most needed them. They could be accessed simply by jumping up and down on them - which, you have to admit, beats using a password any day.
Nevertheless these PCs were only a minor source of comfort when Sonic began his second quest. He soon realised what he had let himself in for - a potential one-way trip through some of the most hostile environments known to man or hog. But then Sonic had to do it to get the Chaos Emeralds and to save Mobius.