Ok so due to the build issues is kinda hard to give propper feedback but gonna do my best:
First of all I've seen quite pleanty of games taking the theme in this direction but this is the first where I feel the echoing is actually the CORE FOCUS of the challenge, well thought out, love the fact that leaving the rift and starting your eco takes brain power.
Main gripe is that with all you have here if there was just a little bit more use of the visual arts in the indications of the game the ramp up (once you get it in order xD) could be way more intuitive and less lead by the nose, allowing the player for some WOHA times.