From Sonic Retro
Iron Ruin is a racecourse in Sonic Drift 2 for the Sega Game Gear. This stage is the sixth track of the Purple Chaos GP - Purple being the easiest of the three tournaments - coming in between Desert Road 1 and Desert Road 2 (2 being the first track of the subsequent White Chaos GP). Iron Ruin is not a cyclic, three-lap racecourse; competitors must race right across the stage, with the fastest racer awarded a Chaos Emerald.
And more bleak or desolate place it is difficult to find within the locales of the Chaos Grand Prix. Iron Ruin is a decrepit industrial wasteland, its skyline clogged with broken manufactories and dark, shadowed assembly plants. Plating the entire region, acres of metallised ground have transformed into lifeless fields of ochre rust, a monotony broken only by the black, yawning pits which appear from time to time on either side of the track.
The obstacles that litter the track here are strange "Reverse pods", which temporarily cause your vehicle to steer left when you hold right, and vice versa.
Sonic Drift 2 makes no unambiguous statements of where in Sonic's world the races are located, but several of the other courses in the Purple Grand Prix (e.g. Casino Night, Emerald Hill, Hill Top) are set in zones that Sonic and Tails visited during Sonic the Hedgehog 2 (16-bit) - and those were on Westside Island. It is therefore possible that Iron Ruin lies there too. On the other hand, some have pointed out that Iron Ruin's skyline looks remarkably like that of Sonic 1's Scrap Brain Zone; to the extent, in fact, that Iron Ruin may be Scrap Brain Zone, seen months after the Doctor's defeat on South Island. There is, alas, no clear-cut answer; and all this evidence is just circumstancial - Iron Ruin could quite easily be situated somewhere else entirely or the racers could simply be alternating islands.