Photopia is really more of a story than a game. It's interesting and it's compelling, but if you're looking for traditional IF gameplay, this might not be your cup of tea. There are no puzzles and not even many choices to be made. But when it all comes together, it works like a well-written short story. And you're gonna have an emotional reaction that you might not have expected.
Photopia definitely pushes the boundary of story-telling in a way that few could have predicted when Interactive Fiction was first introduced. In fact, I would say Photopia is best viewed as an experimental work whose impact is found in later works of IF by Cadre and others.