Kicker—Sacrifice an artifact or Goblin. (You may sacrifice an artifact or Goblin in addition to any other costs as you cast this spell.)
Goblin Barrage deals 4 damage to target creature. If this spell was kicked, it also deals 4 damage to target player or planeswalker.
4/27/2018 You can’t cast Goblin Barrage unless you choose a creature as a target, even if it’s kicked. However, you can target a Goblin or artifact creature you control and then sacrifice it to pay the kicker cost. The target player or planeswalker will be dealt 4 damage.