I'm not sure newer generations are familiar to the
Turrican series. The original was released for 8 bit and 16 bit computers, and it's legendary in its own right. It's a shooter, but the levels are huge and the player is encouraged to do as much exploring as shooting. In some levels, you can even reach next level without facing the bosses, if you know what route to take. All versions are great, but the Amiga one is the one with the real cult following. Then there's the sequel, "Turrican II", that was even ported to PC (MS-DOS only, I'm afraid).
Then there are the console variations. The GB has a pretty good port of the original, in a variety of green colors and with tiny sprites, and the Super Famicon its own "Super Turrican" series.
The Genesis has "Turrican", another port of the original which could have been great, but is just OK instead, because the controls are not as responsive as in the Amiga version, and it's also a bit disorienting finding out which button does what, because there are tons of different weapons to choose from.
But it also has "Mega Turrican", which is the game of the capture and easily the best of the apocriph Turrican games. The first thing you notice is the graphics, which are easily the best ever in a Turrican game, but also the playability. The character moves faster than ever, and the controls are awesome. They added a mechanical rope essential to reach some areas, but pretty much everything is about running and shooting, and it can reach frantic levels pretty soon.
Fans of the original may miss the exploration element, because the levels are pretty straight forward, but otherwise we're talking about one of the best shooters in the Genesis library. And that's saying something.
P.S: Stay away of the "Universal Soldier" games. You may come across them if you do some research on the Turrican series. They use the same game engine and were created by Accolade, who also made the console ports for "Turrican", but they are utter crap.