I tend to look at game lengths by evaluating a game on the slightly above average time it takes to complete it. Sure, pretty much any game can be speed run to a fraction of it`s usual run time, but it`s not really a fault... Any game can be speed run if you know what you`re doing.
That said, the consensus seems to claim the order is pretty much a sub 8 hours game where pretty much half/ one third of that is cutscenes... And the people that played the game were not masters, they were mostly playing the game for the first time... In a game with no multiplayer , and in a shooter type game... Feels way too short, and that`s not taking into account the people that ran it quick and finished it in like 5 hours. Granted, I don`t mind shorter games, but at one point I value my money, and I`m not paying 70 Bucks for seven or so hours of gametime... Even if those seven to eight hours are great.
I mean, at one point it`s not about being cheap ,it`s about not accepting being short-changed by a dev. They had a few years to release a retail game, and the fact they settled in with such a small campaign with no side features does not warrant a purchase.
A game like uncharted , for example, usually lasts about 12 hours or so... And they have a multiplayer mode that can extend the value of the package if that`s your thing.