The game is too repetitive to the point of being boring, but it fulfills the theme.
So, do you think it would be better if I made the experience more focused by shortening the tunnel?
Well, actually, yes, because the game is so linear and practically all you have to do is go down, there will come a point where you get bored because you don't notice any real progress, but if you decrease the distance, more people might enjoy it.