It's a good game, could do better.
I'll deal out the issues before I talk about the good stuff about it. The main issues I have with it is that the 'sonar' as you call it is a bit hard to read at times, but it's good that it's there. The next issue is a small bug I came across, I can't throw the ball anymore. There are times when it could have saved me a headache.
The good parts of the game are the music, the concept of a blind man overcoming many obstacles, and the gameplay.
The music adds a suspenseful feeling to the game, Who's calling for help? What's going to happen? The concept of a blind man going off to help a person in need is an original and great concept in a Platform game, but not so much in other media.
The gameplay is pretty good, the jumping is just right, not too over-hyped and not too toned down; which makes me infer the man is in good health. The speed he moves is slow, which is good seeing as a blind man running around in a place full of lethal spikes would be a bit unorthodox. Another good part of the game I have yet to mention is the detail you put into it. Some people will look at this and ask "Detail? It's a white outline on black with the occasional bit of white that acts like a wall or spikes!" To those people, by detail I actually DO mean those little bits of white. It's pure genius that the main details are the walls, the spikes, and the sudden emptiness that you realize a second too late. A few things like the lamp and the dumpster add to the story, 'What are they there for? why are they here?' This is a game where I actually can think these things without something crazy and/or flashy going, 'Look at me! I'm a Crazy and Flashy piece of random in this game!' This game appears to be simple, but it is much more complex and intricate than people think at first.
I really hope that you can fix the bug in my not being able to throw, then I can thoroughly enjoy this game without getting too many headaches.
9/10, 5/5