The following is going to be a summary of the feelings I had during my first playthrough of ME3:
While playing the first time through ME3, for me there was an atmosphere of impatience, decay, catastrophe and desperation. In the first minutes of the game you have to leave Earth and beloved characters. Throughout the main plot the galactic civilization we learned to like starts to disintegrate. This feeling was fueled by the increased amounts of refugees, systems under siege or already lost, the constant bad news I eventually would listen to, being nearly forsaken by our supposed allies and my seemingly futile actions against an unstoppable force. Some individuals' reaction to this atmospehre would be denial, paralysis or despair.
Yet, in my playthrough, I felt driven, like fighting against the clock. This experience was more intense in ME3 than in ME2 or ME1.
In ME2 some colonies were abducted, but there was no real time pressure with the exception of the last missions and the stakes were high, but not in an "all or nothing" fashion.
In ME1 we had so much time to explore, everything was new, that the main plot, where the stakes were higher than in ME2, did have a certain amount of pressure, but the main drive I had was to proof that I was not some lunatic.
In ME3 the pressure mentioned above is addressed by Anderson's concerns regarding our mental stage, the general tone of everything heading downwards and the dreams.
Now I will elaborate what the whole introduction to this post was all about. The atmosphere was fast paced, driven to avoid the seemingly inevitable, yet the dreams are an anomaly. The movement, the expression of mimics, the sound, everything seems to be slowed down.
In the end, I rushed to the final assault, having in mind the stakes of this risky undertaking. The whole galaxy is under siege or already lost. The pressure culminates to this point, it is "all or nothing". And then I am hit by Harbinger's beam...
The tone of the atmosphere shifts. The slowness of everything, first annoying me, starts to calm me down. After the heated conversation with Anderson and TIM and being elevated to this kid that haunted me in several dreams that foreshadowed this break of the atmosphere of time pressure - I feel kind of light headed, like floating. Feeling diconnected to everything I did earlier, I listen to the suggestions the kid makes. And then I make my decision.
It is remarkable how BW was able to influence me only using visual and sound effects. If they were able to include the other senses (especially olfaction) they could've suggested everything and I'd might've considered it.
PS: I really would like to hear about that theory that has been mentioned earlier in this thread. I am not really sure, why it is withheld and only accessible to a fraction of this community. In any case, this is only going to divide the community in those considered on the inside and the plebs, left outside. I really hope that this is not going to happen.