I got to world 12 once, but I think that's about as far as I can get before the rng hands me either instant game over cause spawned in a wall I guess or too wide an open space with too many spread out enemies.
The most effective strategy seems to be to line strafe when ever able to get vertically or horizontally aligned while letting the enemies ram into your shots. When that's not viable cause stuck with too many at an angle, just twirl around and let shots hit whenever they can. Also the enemies going through walls seems to be the player's best boon.
Tip to anyone else who tries this: don't bother letting go of the shoot button.