Sorry for the delay (mail considered notification a spam so...). There is the bug I was talking about and it was quite easy to reproduce. Just playing through the level, back to title, play again, back to title and bam:
Yeah, turning off reflections and motion blur helped a lot, but the game's still unplayable at full HD on AMD Ryzen 7 3700U (integrated graphics btw) as it is fast-paced. I don't mind switching to 1280x720 and I do this on every game (just for consistency), even though most of them work fine even on native resolution, but I suppose either some optimization or triple-buffered v-sync for relatively smooth 30 FPS would be a game-changer, but I also Don't suppose that such v-sync would be possible to implement or that there is anything to optimize due to overall graphics simplicity.