THIS WAS SO COOL!!!!!! Needless to say, I was spooked. 10/10 would play again.

The other two comments have already summed this up: It is cool as a concept, but exceptionally bad on the execution. Highly recommend taking this back to the drawing board chief!

Very nice concept, but I wish more was done with it

Good stuff: Sonar based gameplay has a lot of potential!

Bad stuff: Not really much going on here- as it was already mentioned in the comments a simple indicator of how many you managed to save and how many remain would help a lot. Clearly temp graphics =D

It's an interesting idea, and doesn't require too much guidance to get started with... I did have to die a handful of times before I figured out what I needed to be doing, but once I did figure it out, it was easy to keep going. There could be a little more interactivity... for example, instead of making a bee line for the ship, maybe the sharks could go after the swimmers every now and then. Some sort of score system or progress bar would also be welcome.