The sonar-like screaming was a cool mechanic - I could see an expanded version of the game include things like walls you need to detect in the darkness. I also liked how the scream effect seemed to favour the direction I was facing, meaning that while I could affect monsters "behind" me, those in front would get the brunt of the scream.
The seemingly-unlimited space combined with the 360-degree attack meant that I could avoid the monsters and slowly defeat them without worry until they became so large that they spawned right on top of me. That said, I think it's nicer for a jam game to feel somewhat too easy than somewhat too hard.