On first appearances I was a little confused, but I'm glad I kept on because I think you've executed the ideas really well. Once I got a hold of the controls and the visual-spatial awareness using echolocation, it made much more sense and I started flapping through the cave with bravado, eating butterflies like nobody's business. The echolocation is quite pretty and gives good visual feedback, whilst making the player have to still look around a bit to figure out where food is. The cave feels very angular and cave-like, and was big enough to get a sense of exploration. I liked the use of the vertical layer too, making me need to duck in places or fly over snakes, kind of like aerial platforming. Good work!
For constructive feedback, I think there might be a few too many controls here - I think most of the game could be played if committed to with the keyboard or mouse. Key-wise, I wonder if setting LEFT and RIGHT to rotate the bat could have felt a little bit more natural. Otherwise, once you get the hang of it, it's no big deal at all. With more development time, I wonder what other features or secrets you could set in a big cave like this to encourage the player to have a bit of a wander around?
Thanks for checking out SYMMACHUS and I hope you had a fun time making Bat for the jam!