Fewer frame drops from wave 10 on, when the sky fills with planes and bullets: enemies, enemy bullets and glowing particles are drawn in grouped batches.
The auto quality governor now always adapts while you play, even after you picked a graphics level yourself (older saves are reset), and after its last step it also lowers the resolution.
Boss fights are lighter on Low graphics: the storm clouds and light rays are skipped there and the darkening is kept.
MACH-X