Please note - This is just a rough sketch of the actual story.

You wake up in a dark strange place with doors everywhere and with no memory. You hear a voice which says that you are trapped and must open every door to reach the exit.
You have to enter the doors to get key to the next door.
These doors are actually portions of the characters subconsciousness and the doors lead to his memories, fears and dreams but in a much horrifying way. Every mission will have choice based gameplay and a moral message to the user.
The memory missions give us the back story of the player who starts to remember his past.
In the end the "user" realises that it's the mind of the character. A evil spirit is trying to take his body and every choice in the game made is now put to effect.
If the player has chosen many morally incorrect options the character gives in to the evil and if he was morally right the spirit finally gets defeated. The protagonist is a person with a military background and he has a wife and a child.

I want some feedback in order to improve it.
Thanks.

Can you sum it up in one sentence?

I like the idea of the character changing into some creature on the basis of moral choices he made. However, could you provide more details? Protagonist sounds to be very trite. And maybe some additional details can bring more originality to the beginning: as I read it I had images of old games with awful graphics (like Doom II).