This game is in my opinion the best SMS game. It has colorful graphics, wonderful sound and a large game world to explore. Combined with the fact it has RPG like elements and it puts games like Super Mario Brothers 3 to shame.
This game was one of the bigger SMS cartridges at 256KB (2Mbit). I chose this game as a birthday present and it kept me entertained for quite a while. To implement a persistent world you were given a password you had to write down. In an ideal world they would have added some battery backed save ram. It was quite frustrating to write the password down and then enter it with the control pad, it was also prone to mistakes and you quickly realized you had to triple check what you wrote down to ensure your game wasn't lost.
If you can only play one Sega Master System game play this game.