Steamworld Dig is a fantastic Metroidvania, but it is one that drilled through the foundational pillar of exploration to define itself. You drill your own path to each treasure giving you a small upgrade. Whenever your progress is gated you tunnel your way to a stronger mining tool. But, your greed will catch up. If you mine carelessly it will be a pain to reach the surface or the area you dug down to last time. If you spend carelessly you will have already pillaged the mine of all it can give. Steamworld Dig deserves a lot of respect, not only did it create a fantastic and fun Metroidvania, it did it in a way no other series has. All while it makes the backtracking common in so many Metroidvania's so much more meaningful since it is due to your actions.