The "Average session duration" metadata input box has never made much sense to me, especially considering you can only set values like "A few minutes" and "About a half-hour". A game saying it takes a few minutes per session doesn't really tell me anything, since it's vague and could be referring to the length of a chapter, the length between checkpoints, the total length of the game, or the length you'll probably play for.

Considering a lot of developers put "total playtime" in their description anyway, I think that would be much more helpful to players in the metadata.

I agree. "Total Playtime" would make more sense and be more useful to players.

I agree that an Estimated Total Play-Time would be interesting.

As for the average session duration, I feel it can be helpful sometimes, but I agree that it can mean a lot of different things.