move_toward only works with floats, i think
so you need two lines, one for x and one for y... and the movement
movement.x =movetoward(movement.x, mousepos.x, delta)
movement.y=movetoward(movement.y, mousepos.y, delta)
or you could make one long lkine... and I'd add a speed , I think, or else its too slow?
movement = Vector2(movetoward(movement.x, mousepos.x, delta*speed), move_toward(movement.y, mouse_pos.y, delta * speed) )