I agree with adding another sound cue for the objective. I'm sighted but am playing without seeing the visuals, and it's a lot of trial and error.
Also, the same thing could be done for the blocks that defeat you. When getting closer to one of those, we should hear a new sound.
Ideally these sound cues can let the player distinguish between left-right and up-down for example with stereo audio and higher/lower pitch for relative up-down. Also distance is important to consider.
This is not trivial to implement, but I think this game has potential to be very fun to play blindly.