I love the Half-Life series. A great blend of puzzle, action, sci-fi, and story. I've heard it defined as a science fiction first-person shooter, but I've also heard it described by people (myself included) as a psychological horror game.
Psychological horror is defined as "a subgenre of horror fiction that relies on character fears, guilt, beliefs, eerie sound effects, relevant music and emotional instability to build tension and further the plot." I feel that this is true to the Half-Life series. Emotions are often (subconsciously) instilled into you, as Gordon Freeman. Guilt is a common fear seen in the games. In Half-Life 1, you are responsible for the outbreak of aliens from the Xen world. All this death and destruction around you is your fault and you have to stop it. Often, you come across a fresh-eaten corpse or even a fleeing scientist that makes you stop and think, 'Was that my fault?'
In Half-Life 2, this is intensified to the extreme. Look around you. Oppression. Starvation. Fear. Everywhere you look, you are met with the downtrodden faces of humans. Us. You see shells of what were once living, breathing human beings. You drive through what was once a most-likely bustling and joyous neighborhood. You hear the forgotten sounds of children, see the husks of teddy bears lying in the abandoned park. This is a world devoid of joy. And you are its maker.
A lot of the fear comes from intense opposition. You're always down to those last few bullets and then you're hit by another wave of zombies. The final battle against the Striders in Episode 2 was one of the most intense and nerve-wracking battles I ever fought in the video game world. Friends fell around me, and every time I heard the cry of a dying Resistance Member, I thought that it was my fault and that I should have saved him.
When Alyx is near-death, you are overcome with emotions of fear and stress. Gordon Freeman, you, love her (whether as family or as more depends on your personal feelings toward the character) and you want to protect her. So despite the lack of a time limit, you speed yourself up in the caves to save Alyx. You put yourself forward against the Antlions for her.
Finally, the ending. The ending of Half-Life 2: Episode 2 ends on such a sad and unfortunate note that I barely kept myself from tears. You were given a job to protect Alyx and her family and you failed her. It's your fault.
Most of the fear of the Half-Life games comes from not knowing if you will succeed. Considering the games are relatively easy, you rarely die and thanks to the storyline you are rarely pulled away from it. You become Gordon Freeman. You take on his fears, his shortcomings. You are Gordon Freeman, and whatever you are, he is. That's why I believe Half-Life is a horror game.
Tl;dr: HL/HL2 is scary cause of emotional terror, not "OMG BLOOD & GORE" terror.
Psychological horror is defined as "a subgenre of horror fiction that relies on character fears, guilt, beliefs, eerie sound effects, relevant music and emotional instability to build tension and further the plot." I feel that this is true to the Half-Life series. Emotions are often (subconsciously) instilled into you, as Gordon Freeman. Guilt is a common fear seen in the games. In Half-Life 1, you are responsible for the outbreak of aliens from the Xen world. All this death and destruction around you is your fault and you have to stop it. Often, you come across a fresh-eaten corpse or even a fleeing scientist that makes you stop and think, 'Was that my fault?'
In Half-Life 2, this is intensified to the extreme. Look around you. Oppression. Starvation. Fear. Everywhere you look, you are met with the downtrodden faces of humans. Us. You see shells of what were once living, breathing human beings. You drive through what was once a most-likely bustling and joyous neighborhood. You hear the forgotten sounds of children, see the husks of teddy bears lying in the abandoned park. This is a world devoid of joy. And you are its maker.
A lot of the fear comes from intense opposition. You're always down to those last few bullets and then you're hit by another wave of zombies. The final battle against the Striders in Episode 2 was one of the most intense and nerve-wracking battles I ever fought in the video game world. Friends fell around me, and every time I heard the cry of a dying Resistance Member, I thought that it was my fault and that I should have saved him.
When Alyx is near-death, you are overcome with emotions of fear and stress. Gordon Freeman, you, love her (whether as family or as more depends on your personal feelings toward the character) and you want to protect her. So despite the lack of a time limit, you speed yourself up in the caves to save Alyx. You put yourself forward against the Antlions for her.
Finally, the ending. The ending of Half-Life 2: Episode 2 ends on such a sad and unfortunate note that I barely kept myself from tears. You were given a job to protect Alyx and her family and you failed her. It's your fault.
Most of the fear of the Half-Life games comes from not knowing if you will succeed. Considering the games are relatively easy, you rarely die and thanks to the storyline you are rarely pulled away from it. You become Gordon Freeman. You take on his fears, his shortcomings. You are Gordon Freeman, and whatever you are, he is. That's why I believe Half-Life is a horror game.
Tl;dr: HL/HL2 is scary cause of emotional terror, not "OMG BLOOD & GORE" terror.