For many years I actually thought that Sonic the Hedgehog on the Master System was the same as the Mega Drive version only with 8-bit visuals. Not only is it a completely different game but it actually came out almost 6 months after the Mega Drive original.

There are some similarities, the opening stage is a version of Green Hill Zone (Complete with a nifty version of the level music) as are two others leaving 50% completely original locations. The general gameplay and structure of the game is also the same with several levels per each of the 6 zones followed by a fight with Robotnik and freeing the animals he captured as was the original game's premise.

The rest of the zones contained are different for both better and worse:

Zone 1 - Green hill - I like this zone, it's an easy going classic, there are reasons it or variations of it are normally starting zones
Zone 2 - Bridge - this is weirdly for a sonic game an auto scrolling zone. It kind of works though as this is a much slower paced platformer like it's Mega Drive counter part
Zone 3 - Jungle Zone - I have issues with this one listed below
Zone 4 - Labyrinth Zone - Another similar level from it's big brother, I like the underwater Sonic levels though I know I'm a minority there
Zone 5 - Scrap Brain Zone - So much better than it's big brothers version again, easier and less frustrating
Zone 6 - Sky Base Zone - I liked this level, had a great atmosphere

Of all the zones the only one I wasn't keen on was the Jungle zone. there is a section that's a bit tricky where you climb up a waterfall jumping on ledges and rocks. once the screen goes past a platform though it locks meaning if you try to jump back to it you instantly die even if it's a millimetre which is just kind of stupid. Other minor gameplay annoyances including how the rings work as the amount only matters for gaining extra lives. If sonic takes a hit he loses them all with one visible ring dropping you can't collect so essentially you only have the one hit to take regardless. The boss levels you don't have any rings at all though I kind of liked that as you had to learn the pattern and play skilfully. The bosses themselves aren't brutally hard though, especially to a seasoned Sonic player. Interestingly when you collect a bubble shield from a TV though it does transfer between levels so you can head into a boss with one as a possibility, I liked that.

There are Special Zones accessed through non boss stages when finishing with more than fifty rings as the only other use for them. This gives you the chance to get extra lives or continues by bouncing on springs to the end of the level in a time limit. There are no chaos emeralds here though, for a bit of a change they are actually hidden in the main levels requiring good jump control, using invincibility boxes to reach in spikes etc.

The game handles really well, the jumps and animations feel like a Sonic game should. The visuals and art design are the level of coloured and varied as I would expect, though the tiny enemy models are hilariously cute. The backgrounds are pretty static but Sonic's character model and animations are really well done. Interestingly this is actually the first game made by Ancient, the company formed by legendary composer Yuzo Koshiro. It was initially created to make this game specifically and it's Game Gear counter part before going on to later fame making Streets of rage and Beyond Oasis.

Overall I had a good time with this and the thing is I didn't expect to. It looks really nice for an 8-bit game, has a banger OST and plays well with some neat little ideas. Not everything works but overall it's a good little game.

+ Nice visuals and music.
+ Zones are fun and varied.
+ No ring bosses and emeralds on stages are different.

- Jungle Zone instant death isn't very well designed.
- Losing rings all at once is kind of lame.