* Silver Surfer can only take one hit before dying.
* Most of the game's enemies take multiple hits to kill.
* Silver Surfer dies upon touching any obstruction in the level. This difficulty is compounded by the fact that his surf board is large and open areas are very small.
* Most of the time Silver Surfer is being attacked by large numbers of enemies coming from all directions, some of which can shoot.
* The movements of some of the enemies (particularly in Mephisto's level and the Magik Domain) are extremely erratic and rapid, which makes them unpredictable and hard to dodge.
* In some levels, it can be hard to tell what bits of scenery are obstructions.
* Whenever Silver Surfer dies, he has to restart the level from either the start or a checkpoint. Continues are limited.
* Silver Surfer can only go in a straight line, and threrfore cannot enter slanted areas without dying.

Just to clarify: the game is actually called Rygar, Contra is a whole other game.

http://www.consoleclassix.com/nes/rygar.html