First Person vs Third Person

[Greeny]

While it's true that first person is not ideal for descriptive passages, as it happens in Visual Novels you need to cut back on the description anyways.

Protagonist doesn't need to tell me what colour the car is, I can see it on the screen!

[SusanTheCat]

And if it is something off screen, you can still use the first person's voice to give a description and characterization at the same time.

"The last time I saw Michelle at one of these parties she was in a green dress-thing with fru-fru stuff around the legs."
vs
"At least Michelle wasn't wearing that emerald handkerchief hem gown she was sporting at the last affair."
vs
"I wondered what happened to the green dress Michelle was wearing at Samantha's party last month. It looked really good on her."

Susan

[Ferdokki]

Either perspective is fine to me, but it all comes down to what the story is about.
For your game, you specifically said that it is about a child in slavery, and the child does not grasp onto certain concepts the way adults do. In that case, I would advise you to make the game in first person perspective, so that we can see and experience the world through this child's eyes.

Maybe in the part of the game starting after when the character escapes, you can switch to third person. Idk how well that is going to be accepted though, but it's just a thought.

Good luck!