Sega and US Gold was never released the Sonic series to the ZX Spectrum. Nor for the Commodore 64. This was only for commercial reasons: they wanted to sell the Sega MegaDrive in huge quantity, and forced people to buy the machine simply for playing the Sonic game. At the same time, widespreading of 16 bit micros and consoles, they did not remain much interested in the 8 bit market.
That's why Anestis Koutssoudis from the Greek Spectrum Club take again the Sonic series. Very impressive intros and nice background- and ingame graphics saw the light from the game.
The author gave the source code and the half-ready game to free to public access believing the faster realisation. By his plan, the game will be monochrome - opposite of the pictures - because only that way can remain the gameplay dynamic. No news since 2001...
