The code below solves the issue, but.. it's not the cleanest way to solve a problem.
before I was simply using var velocity = Vector2(0,0) and move_and_collide(velocity)
if (_marioDirection !=0):
_spd += _moveIncrements * delta
_mDirection = _marioDirection
else:
_spd += -_moveIncrements * 1.5 * delta
_spd = clamp(_spd, 0, _maxSpeed)
_jumpSpd += _gravity * delta
_velocityx = _spd * delta * _mDirection
_velocity = _jumpSpd * delta
move_and_collide(Vector2(_velocityx,0))
move_and_collide(Vector2(0,_velocity))
However, as soon as I'd hit the floor I couldn't move horizontally, am I doing anything wrong?
Thanks.