Tell that to the Warcraft film. And Spiderman game too.
Can I go to the movie theater with my mouse and keyboard and control and change the events unfolding in the Warcraft movie?
Can I insert the Spiderman game disc into my console, sit back on the couch, throw the controller out the window and watch the game play itself without any input?
The answer to both is "no".
Gradation is a concept. Story which begins with a big boom then fade out on the end are not very often, becouse they are not very successful.
Gradation in terms of story is good. That's one reason why the several-waves-of-voidlings fight is great. It is a surprising, tense encounter which doesn't have a certainty of when it will end, AND it promises that there will be later encounters of a similar nature, but even more difficult.
However, what works for story does not always work for gameplay.
Each act can and should build up combat encounters until at the end the final encounters of the acts are both thematically appropriate and tactically challenging.
However, I do not agree that the game should enforce a DRAMATIC CLIMAX on the player by arbitrarily limiting their options just to make it more dramatic. To me, that is taking away too much freedom away from the player.
