Congrats on the submission. I found the timing to be really hard, and I wonder if the combination of moving the turret and moving targets make it too challenging - potentially there could be additional audio cues to help "lock on".
I'm also surprised at the different Text To Speech between the beginning instructions and in-game readout. The in-game readout for me was really hard to understand and sounded like a raspy wisper. The starting Text to Speech was so much clearer and easier to understand - it feels worthwhile to just have that one.
Note: that was on Mac OS X, when testing on Windows, the default voice was easier to understand. There may be some settings or configuration to change there to make it easy to understand on both.