One of the key selling points was that Sonic 2 is generally faster than its predecessor, and this is partly thanks to the level design, where stages such as Chemical Plant Zone feature long, twisting and looping stretches of ground to run along at great speed, creating some of the fastest experiences of the early Sonic world. You'll fight the boss at the end of each second act, and as with Sonic 1, Eggman strikes again in all new contraptions, each requiring eight hits to defeat.
They're long enough to enjoy them properly though, and somewhat easier too. Admittedly most of them are quite brief, and except for the later ones, each is divided into 2 acts, while Sonic 1 carried 3 acts per level.
Sonic 2 is probably the biggest single 2D Sonic game so far, with a whopping ten levels (final boss stage not withstanding), as opposed to the average number of six or seven.
