Difficulty spikes aside, Dr. Robotnik's Mean Bean Machine is one of the most addictive puzzle games on the Genesis
To start with, it seems as though they decided to base the game on not the Sonic games, but the cartoon "The Adventures of Sonic the Hedgehog" judging by the characters and art direction. The evil Dr. Robotnik is capturing these creatures called "beans" from Beanville and robotizes them to make sure there is no more fun or music in the world of Mobius (eh, it was the 16 bit era, nobody cared about story at that time). I guess you, the player, are the hero who has to stop him this time? Seeing as how Sonic doesn't show up to stop him like he always does let alone the fact that he's never mentioned.
Similar to Tetris or Puyo Puyo, the game is played with two opponents, each controlling one of two grids. Beans fall from the top in groups of two, coming in various colors and one pair falling at a time. You want to arrange the beans into groups of at least four beans all of the same color. When you do this, the beans in the group will disappear. Create a combo of these beans (as in set off a chain reaction) and rocks will fall in the opponents grid, cutting him off from the rest of his beans (the amount dropped depends on how big the chain was). You can clear these beans by creating more groups. The first player to fill his grid to the top with beans is the loser. This is a pleasantly difficult game that takes much careful planning, strategy and skill to accomplish. Playing long enough to learn different strategies on how to stack your beans is always fun and you feel accomplished if you were to learn how to play the game well.
The single player mode is pretty much playing with this gameplay several times against each of Dr. Robotnik's creations, and eventually Robotnik himself. The robots you take on are once again taken from the cartoon it's based on like Scratch, Grounder, Coconuts, and several others (although the 3 I mentioned are the only recognizable characters from the show, the rest are background characters). After every 4 characters you beat, the game gets harder as the beans now drop even faster than before. This mode is fun and watching their reactions when you're beating them is even more satisfying, but the one problem is the large difficulty spike early in the game. The first two are easy as pie but somehow the game gets really difficult by the 3rd or 4th robot. This mode is not recommended for the easily frustrated.
The campaign is good for a warm up and an introduction to the gameplay, but the real fun of MBM is the multiplayer. It plays like single player of course but both players can choose their own, separate difficulty which is a fantastic way to balance the game for experienced players and newcomers, or you can just choose the same difficulty and have an even chance. There isn't anything new besides that, just fill your opponent's grid before he can do the same to you, but playing with another player makes it all the more fun and intense (especially with that awesome music playing).
Dr. Robotnik's Mean Bean Machine is one of the most addictive puzzle games on not only the Genesis, but from that same era altogether. If you can get passed the uneven difficulty in the single player mode, the gameplay is challenging yet satisfying, especially the multiplayer. Today, I still consider this little gem to be one of my favorite puzzle games from my childhood and possibly of all time. I recommend this to those who aren't easily aggravated or those who are looking for a charming old school Tetris-styled puzzle game.