Thank you for the comment.
I've updated the game and added more choices in the "Pause/Options" menu, so now you can turn off "Lights", "Decorations", "Effects" and move sliders "Falling Fire Quantity", "Shadow Distance" on minimum. Also you can try "Look Distance" slider, but on low values it may look weird. Hope it'll work for you.
By the way, now you can download standalone versions for Linux and Windows.