It is a lovely little game. I think the first problem is in your marketing script. You call out negatives (doesn't have plot, soundtrack, etc) right away. I actually was expecting a silent game from this. Instead it does have sound effects, even if minimal. Regardless I don't think drawing attention to the negatives helps you. I also think the hole and wall graphics aren't helping sell it - they don't 'fit' all that well in my opinion.

Despite that I do think you prove the point that the previous poster requested. Unfortunately yours is one of many examples of well-done apps that doesn't get traction.

Do forgive the critique, I hope it will be helpful to you in going on to make ever more amazing apps. And I'll curtail my suggestions here. :)