Contra 4 is fun if you are
a) a masochist
b) an old school 2d shoot 'em up fan
The game loves the fact that it is incredibly hard, and in fact mocks you if you choose to play on the easy level. There are 9 levels to the game and each time I make my way to the next I swear that it is impossible. Memorization is the key to success, and you will have to play each level probably a dozen times before you figure it all out. Get hit once and you lose a life, you only get 5 continues, but if you stop and save the game they take a continue away from you.
Oh, and the Contra code is not included.
I have heard that if you complete the game you can unlock the original Contra and, I believe, Super C.
I love it, if for no other reason than it feels like I have gone back in time to when games were really hard.