I have just started to come up with my idea for my first game. And i would like people to give feedback to my idea. I would prefer brutal honesty, as it would let me know better what is wrong.

I have finished coming up with two characters: The protagonist and the antagonist, though at this point i lack a name, sorry.

This feels like an extremely early concept for a story within a game. You've got some basics going for ya, protagonist and antagonist are essential to a lot of stories, but now you have to decide the kind of game you're making, and how you'll incorporate the story.

All the advice I have to give is to make your game the story, not put a story in a game. Anyone can make or watch a movie, anyone can write or read a book, but it's very tricky to get a story into a game because the story has to be happening to the player. If you can do that, people will care about your story.

Good luck bro

Both of your characters contradict them self.

Your protagonist, lets name him Mary Sue, is a manipulative, introvert who killed his own parents for cash. Mary doesn't sound like the kind of person who would even have real friends, he definitely wouldn't care about how others feel about his actions.

Introverts are not spontaneous, it's the reason thy have comfort zones as narrow as a single apartment. Ask a introvert to go out at short notice and thy would respond with a excuse thy had stored away for just such a event.

At least thy do tend to be manipulative and there lack of friendship does give them a less than normal level of empathy, so such a person could commit murder although it would be a extreme case.

Your motivation is a lie. So what is the real reason, Cash?

Wouldn't a intelligent person realise that there are easier whys of making money with less risk?

Introverts fear change not stagnation.

If Mary does need a companion it could be a nurse or caretaker who watches over them.

A person who's family was killed in front of them and investigators discover that person lived a life of abuse, it would make sense to get them some professional help.

Now the Antagonist, name: Gary Stu.

A logical person who pays some random person to kill there own family and then that person has to kill Gary, this isn't logical it's insane.

Why did he chose Mary, why kill the parents?

Gary sounds spontaneous, charismatic, rich, a bit insane and most importantly he sounds like a extrovert.

He is dying and fears death, he just paid some random person to kill him.

He pays a large amount of body guards to fight, yet has people kidnapped instead of payed for experiments.

He needs to fight to stay alive, instead of going on some kind of rampage or just attempting a near impossible task(like finding a cure for a disease) he pays a single person to attempt to kill him.

Why does he need to fight?

Does the adrenaline, blood or soul from his victims keep him alive?

Couldn't he use his huge amount of cash to get what he needs instead?

Edit: Spelling and such.

I'm no expert--and stand for correction--but I sincerely doubt this. Introverts can very much be empathetic, just as can extraverts, as far as I'm aware. (Additionally, introverts are more likely to have fewer friends than extraverts, but also tend to have a stronger bond with their friends than do extraverts, if I recall correctly.)

You are correct. Normally being a introvert or extrovert would have little to do with how much empathy you show others, in fact study has shown that introverts dislike others embarrassing them self as much as thy dislike being embarrassed.

It's normal for a introvert to have one or two friends who are very close to them.

It's just hard to see the protagonist as a normal kind of introvert.

The key here is the level of abuse that the protagonist suffered, for the protagonist to murder his parents it has to be some kind of harsh abuse.

Even people who don't have a strong relationship with there parents wouldn't consider killing them for cash, most people wouldn't even kill a stranger for any sum of money.

For some reason the protagonist didn't run away, because he accepted the money from the antagonist it's safe to assume he couldn't survive on his own.

So it was a level of abuse that couldn't kill him, yet still so bad that at the moment he was offered a chance to live on his own that he killed for it.

If the protagonist had close friends, wouldn't thy defend him?

I could see friends not helping if he was bullied at school from time to time, yet he was bullied ruthlessly. Would you be able to face a friend who you abandon each time thy get bullied on?

Would a close friend just look the other way when a friend is abused by there parents, and what if the friend didn't look away?

If you where the helpless friend who couldn't stop the bullies, who couldn't save your friend from his parents, would't you immediately know what happened when you see them after the murder?

This is the friend who stood side by side when some huge kid at school fought against protagonist, this is the friend who lied to the parents when thy asked where the protagonist was. At the moment the two meet after the murder the friend knows, and the protagonist knows he knows.

The only question left is does he abandon the protagonist or does he help him?

You will notes that the friend didn't even consider that there is cash involved, this is simply because when two opposing forces meet sooner or later one a side loses.

The protagonist might refuse the money, he doesn't need extra incentive the fight isn't his alone and accepting the money with out consulting his friend would be a insult to all that thy have been through.

The protagonist I see is the kind of introvert who gets home, immediately go's to there room and pretends to sleep so that hopefully thy would be spared.

This is the kind of person who isolates them self from others to avoid more danger, thy lose empathy with the world because thy feel that no one empathize with them.

The reason I believe this to be the protagonist is because the game starts after the murder, for the protagonist with a friend the antagonist is nothing special he has survived worse.

Possibly more related to "writing" than game design though?