So I tried it again after your explanation and now I got it. I was pressing the red button and not holding it, so I didn't see any movement in my first try. Now due to extending cable, the movement is obvious. Also for the first time, when I tried the blue buttons, it was changing the scenery, but felt more or less like random change. At this point it was quite clear what to do.
As a feedback I think, that it CRT shader is nice, but yes, it contributed to the feeling of automatic movement. Maybe if it would be rotating like "radar" instead vertical movement - but again this is based on my first impression, when it wasn't clear to me, how to play it correctly.
Also I think, that if buttons would have more symbols, it would be better (e.g. arrow up and down, at the top showing symbol of rope/cable going out/in)...
But I still think, that it is very atmospheric game (sound effects and visuals are great) with a lot of potential ;