If anyone has a problem with lasers, the mechanic is tied to the framerate so it's impossible on some screens (tested on 144Hz - instant death, 60Hz a breeze).
Thanks for playing! I'm such a Godot newb :) I'm still getting my head around all the different function calls for processing, physics, rendering etc. ... it didn't occur to me that a 144Hz screen would call that function faster than a standard display :) Thanks!