The game is awesome, I love it. The story, the graphics, the music, super well works together.
The only issue is the controls. Would be perfect to add gamepad support with twin-stick controls.
One tip for the mouse, unless the aiming direction constantly changing as the player moves is an intentional choice (which is pretty annoying and hard to control), instead of relying on a relation between the player position and a mouse cursor position, it would be better to rely on a relation between player position and a "virtual" pointer bound to the player's node (so the virtual pointer moves with the player). Then every frame add a real mouse delta to the "virtual" mouse position and viola, the aiming direction doesnt change when the player moves anymore. The virtual pointer should also be bound to a maximum radius around the player so it doesn't get too far.