The Genesis definitely made a game that could compete with the Snes version. Definitely!
Hyperstone heist allows you to use the four turtles just like in Turtles in Time and it is true some of the levels are the same but very quickly, it changes! There are different enemies and the levels are longer, with less levels. The story is somewhat of a combination of movies and other aspects of Turtles lore.
Instead of Shredder throwing the turtles into a time portal, Shredder has in his possession, the Hyperstone and so he uses it to shrink Manhattan Island and it's up to the turtles to stop him.
Instead of having 10 levels, there are only 5 but they are all longer. Some of the bosses are the same such as Baxter Stockman and Leatherneck but they are slightly different such as Stockman being in a spaceship.
If you watched the first feature film, you may remember that Shredder had someone named Tatsu and so he makes an appearance in this game as one boss.
The game plays almost identically the same. Fortunate for us, the gameplay is still solid and enjoyable. One difference I did not like was the sound. Though some say the sound was superior, I feel as though the sound in the Genesis version was a little inferior. The sounds were a little unclear and that bugged me a bit.
Other than that, this game is still quite good and like I said before, plays like Turtles in Time. I think you have a Genesis and haven't played this game, you should give it a try but you have access to a Super Nintendo, I think Turtles in Time is the superior version.