Idea: Crashing Into An Unknown Planet!

When I thought of this idea, I was trying to think of stuff more in the science fiction area.
It takes place in the future, of course. When Samuel Steelie, AKA Sam, joins a spaceship crew, he is disappointed to find out that it's only repairs. But an unexpected asteroid shower on a trip to Mars hits their ship, everyone on Earth soon thinks that the crew is dead.
But Sam wakes up in the wreckage of his ship, and 3 of the 13 of the crew is dead. He finds himself on a new world. He soon discovers that most of the crew is dead, with the exception of the Captain and First Mate, Communications Officer, and Programing Officer (and him).
The natives of the planet soon take Sam in. He is dubbed by the alien chief as Rescuer From the Stars Above, and is assigned to destroy the Nivco, a weapon of unbelievable power, and Sam soon sees why he needs to save the planet, called Gloyl by the natives.
But where is the rest of the crew? Are they behind this in any way? Or are they being held against their will, or lost?
And can Sam, a normal human, stand against the evil forces behind the Nivco? In a world with amazing powers? Powers that make this world a fantasy planet?
WILL SAM SURVIVE?!?

(Sorry, got carried away when I was writing this post)