So the graphics are a bit dull and the music and sound effects, too. Still, the Genesis version of Risk is a solid port of the classic boardgame. You can play with up to five players, human or computer, choosing the skill level of any computer-controlled opponents (novice, intermediate, or expert) at the beginning of the game. The only thing that I didn't like is that all the human players have to use the same controller (even with only two players), which makes for a lot of passing the gamepad around. In addition to offering traditional play, this Genesis version also sports an "arcade" mode, which plays exactly the same as the strategic mode except that a battle is determined by how well you can aim and fire your cannon.
If you like the board game then you will want to play this. If not, you will probably find Risk to be a tedious affair.
TIP: go for Australia first. :)