Really enjoying this, once I got a handle on it! Took me a few games to realise that I could use the crank to refill my shooting energy :D before that I was like "how I am I supposed to survive more than one level!"
I've noticed the performance degradation by the time I reached a depth of about 5 or 6, will remember to restart to fix that.
One time my ship got a huge laser boost which meant that when I was shooting enemies, they were flickering so much that they were invisible more often than they were visible. This was probably down to having so many lasers and enemies on-screen at one time, and the fact we're playing on a Playdate!