impressive record! You beat my high score by over 100. I'll definitely investigate the beetle spawning to see if there's any chance they spawn within the screen boundaries. The only other possibility is the screen wrapping effect could feel a bit disorienting and appears like new beetles are appearing from the middle..
I could definitely see some room for expansion so I may return to this one day with a bit more development. What would you like to see in a more fully developed version?