Hello, I found this logline almost good,
I just wonder if it respects the structure of the script. I mean, I'm not sure if the movie will be about a journey to escape a fantasy world (Truman show/thirteen floor/dark city), or, people from a fantasy world that look for their creators in our world (like ?fishes out of water?/last action hero).
I think you should make a creative decision about that. In one case the inciting event would be when the characters discover their fates are determined by a sort of game and the resolution would be when they met their creators at the end, in the other case the second act would start when they leave the fantasy world.
Finally, I suggest to find a better description of the fantasy world that a "high fantasy world": try to find one or two adjectives that point out the specificity of this world, or just say "fantasy" if it's a kind of "standard" fantasy world.