Hello! Welcome to Feedback Quest 6! My name's Hythrain, and I'm one of the hosts and streamers for this event! This feedback is being written live on my stream.
This was a fun prototype game. I got to level 32 in my second run, so I felt pretty proud of myself.
Since it's a prototype, I won't comment on things you can do to expand it as these would be things you would come to naturally. Instead, I'll cover things that the prototype should have that it didn't.
You had use of music but no sound effects. I would say a sound effect for shooting and one based on each ship when it spawns (which happens off screen) would go a long way to prep players for what's coming and let them know when they've fired (there were times I would narrowly stop someone but would never see a shot). I would also suggest some sort of meter that indicates shot cooldown (you could do a circle effect around the turret, where once it fills it'll vanish and you can shoot). Finally, I played this on a computer and felt I was punished a little more for it, as if I wanted to turn faster I needed to keep my cursor in the middle. An easy way to alleviate this would be to allow for a sight line from the turret. That way, the player knows where it is and it's simply a matter of reacting fast enough.
Other than this, I loved this and I hope to see it expanded on.