Preview - Sonic the Hedgehog is a two page preview of Sonic the Hedgehog in the July/August 1991 issue of the Italian magazine Computer and Video Giochi, which is the Italian language version of Computer & Video Games. Many of the images are from an early prototype. It also mistakenly says there are 15 levels split into 5 acts, even though 5 Zones are shown total. The first page also mentions a power-up which gives Sonic invincibility and Speed Shoes at once, which is probably a reference to the Unused S-monitor which has been found in the game.
It also mentions that US Gold bought the rights to port the game to the home computer, meaning that Spectrum, C64, Amstrad, ST, and Amiga ports could have been in the works. Of course nothing became of this.
The English version of this page can be found here.