Please try the new version 1.2 and let me know what you think! I've fixed the settings issue, sped up the blaster sounds 4x, and added a previously unused ship explosion sound.
Marvelous! Wonderful frantic gameplay! Sounds are better, but the pew pew is still a bit shrill. The two-note explosion sound you added is right out an Atari 2600 :D The boss in Wave 3 that looks like a stealth bomber is very tricky to nail down, which is not a complaint. The asteroids seem to be immune to the gun and must be dodged?
Suggestion: It would be cool if the B button fired high-rate automatic fire to deal with asteroids. It could quickly overheat (suggest 1.5 seconds with a 4 second cool-off period) to discourage its use as a primary weapon. Being able to destroy asteroids in this retro-vector style would be nice and meta as the game asteroids was also vector. You could even shape them like in that old game so no one misses the reference. Also the deep boom of those asteroids flying apart.
Really cool game, man.