CommanderVideo gains consciousness, and his first thought is a question. What is that? He attempts to look at himself, and he doesn't understand what he sees. A possible metaphor for this is the appearance of the Arecibo message, a transmission containing basic information about Earth and humanity, sent from Earth to any intelligent life that might find it. It's information, but it's unlikely that any intelligent life out there would understand it; the only reason CommanderVideo recognizes it as information is because he's looking for it. CommanderVideo doesn't recognize anything about what he finds, not even his own physical shape (which is present in the Arecibo message as shown, replacing the pixelated human form). The ghostly Commanders that float by further ignite his curiousity about the shape that he has found. He doesn't know that it is him. He doesn't know that there is a him.
It does not occur to him for many years that those figures are there for a reason.
At the beginning of "Descent" CommanderVideo attempts to take a step but falls flat on his face. He decides to take matters into his own hands and go searching a mysterious world. He looks inside, and finds great rivers flowing with a red substance. He follows them to their destination and source, a massive red... thing. It is all very strange and wondrous, but it means nothing to him. After all, he has not yet encountered society, which has placed meaning and significance upon that which he has found: his heart.
Then he looks in between the red rivers, and finds something bewildering and amazing. Constant flows of electricity, seeking and making new connections between nodes. He has found an incredible thing that exists to form connections, to process information, to think. What it is isn't nearly as incredible as what it does. His wonder turns to revelation when he comes face to face with something completely alien to him, yet utterly familiar. Himself. A bright red Core spins in the background, representing something very important that he has gained.
He again attempts to step and succeeds. His first step... no, his zeroth step. Before every one, there is a zero.
And then he moves toward the light. There are others like him out there. They seem excited. And then he speaks his first words. They are the answer he sought, and his first learned truth: "I AM ONLY A MAN", to which his mother answers in kind.
I think that is the reason BEAT and FLUX play the same way. They both represent the times in our lives when we aren't quite alive in the conventional sense, yet we still exist. Our standard notion of consciousness isn't really part of the equation when we don't have bodies yet, which I guess really simplifies things. That's probably why BEAT and FLUX are the most simple, and arguably most consciousness-freeing games in the series.
That said, the goal of a sperm on its way out of the body, and the goal of a soul on its way to the afterlife aren't entirely the same. As such, BEAT and FLUX also have their fair share of difference. Chief amongst those differences is motivation. In BEAT, your main goal was to survive until you get to "the end," which makes sense, as that's also the sperm's only job. In FLUX, survival isn't really an issue anymore, which makes sense, as you're already dead. Instead of survival, the post-death soul is motivated to take what it has learned from human existence, and move on. That's exactly what you do in FLUX.