I need some feedback on this idea I had.

I'm currently making a story about a little girl in the apocalypse. She lives in a basement and she was locked up there by her father. Every day, her dad arrives to visit his daughter and sleep, before leaving the next day to scavenge for food and supplies. The father tells the little girl that there are monsters which can mimic the voice and appearance of humans, and to never let anybody inside the basement. One day, she hears a knock on the basement door. She asks who it is and her father answers. She remembers what her father told her and she hides under her bed, because her father has always had a key to the basement door. She hears banging on the door and pleas from her "father" to let him inside. Now, I have two ideas for an ending. The first of which is that the daughter lets him in, and he tucks her into bed. As she falls asleep, she hears a muffled voice and a slimy hand covers her throat, and she is implied to be choked to death. The second ending has her not let her "father" in, and he breaks down the door. He searches the basement, and then leaves after not finding her. She waits for hours for her father to return home, but he never does. Eventually, she decides to leave the basement for the first time in her life. She finds an abandoned building and a man approaches her. He gives her a glass of water and she feels very tired. She passes out and hears a muffled voice as she sees the mans face split in two, revealing a mouth with several rows of teeth.

What do you think? I think there could be some room for improvement, especially because I don't know which ending I should pick. Any feedback is appreciated.

Also, one more thing. I want to become a game developer, and people have said that this would work better as a game instead of a short story, what do you think is the better medium to adapt this story to?