A really fantastic and innovative horror game concept
Pros: VERY engaging, I'm an absolute sucker for a horror game that takes away one of your senses and this was very well done. Great sound design, amazing atmosphere, I love the innovative way you utilized what you had. No textures? Make it a mechanic. No monster model? Make him invisible. But for all of the simplicity you managed to make it all work in the world and mechanically which is very impressive. I also appreciated the added challence of collectibles and I ended up dying staying in the house to find the last one, got all 3 though. The floor creaking happened just often enough to make me panic when it surprised me, and you made it easy enough to avoid the monster that you did a great job of keeping up that sense of dread without desensitizing me to the threat.
Cons: when the jumpscare DID happen it was slightly underwelming, granted I play a lot of horror games so it takes a lot to actually get to me, the buildup was scarier than the actual jumpscare which isn't the worse thing but it did make me more fearless on my second run. The ability to intetnionally make noise to steer it away was a cool idea but I never felt like I had a reason to use it because A. pinpointing the monster's location is too hard and B. if you're just patient it's easy to avoid it without the props, would have been cool if there was maybe a scripted event that forced you to use on of the props to get the monster to move
Overall one of my favorite horror entries here, I've seen the ecolocation concept before but it was definitely very well done.