Dave Made a Maze (2017) on Netflix

Plot summary

Dave is thirty, jobless, supported by his parents, whom he believes have grown tired of him. Annie, his girlfriend, is out of town for the weekend, so he works on his next big art project. He tends to leave things unfinished, but he has a breakthrough and builds from the center outward. Annie comes home to a small cardboard fort whose inside is supposedly larger than its outside. Dave talks to her through the vents he added and warns her not to enter or destroy it. She shakes the exterior and hears machinery and noise within. Annie calls Gordon, who gathers Leonard, Brynn, Greg, Jane, Harry and his film crew, a hobo and two Flemish tourists. Harry tries to get a reaction from Annie for a documentary. The group goes in.