Might seem unfair, but the button layout is atrocious in my opinion. If you're forcing players to use the Arrow keys or the WASD, then show the icons on the screen in the same layout. Or at least let us rebind them to something more sensible, that is that the buttons would be all in a single row, like VBNM.
I can't even get past Easy mode because the physical button layout and the one displayed on the screen just messes up with my spacial awareness.
It might just my own personal opinion, but I can't even play the game because of the button layout.