Interesting assay into what makes an interactive entity a videogame. For myself as many if it's entertaining I persevere, but if it's exceedingly pointless according to my biases I will just drop it.
I was considering making this a topic soon myself, so thanks for doing so. I played and beat several games recently that some may consider "not a game", namely To The Moon, The Walking Dead, and Dear Esther. One thing that I think sucks about categorizing these as "not games" is that I feel some people who would love them, avoid them because of the label they have attached to them and that's sad, becuase there is some really cool stuff to be found here.
Let strength be granted, so the world might be mended...so the world might be mended.