That's very cool. I think I'll use it to help me decide the order in which I work through my backlog, which is some 30+ games deep at the moment.
If I have a couple of weeks with not much on, I'll pick a game with long completion time; otherwise I'll search for something I can plausibly beat in a timely fashion given however much free time I'll have.
Also seems like a feature people might like included on Archive.