SteamWorld Dig is a partially procedurally-generated Metroidvania-style platformer.
Not much to write home about. Rusty has been given the deed to his Uncle Joe's mine, only to find Joe perished while he was on his way. Noting that it was a strange move to send it to him, Rusty continues to dig down in the mine to uncover the mystery of what Joe found. As his travels take him deeper and deeper, he finds more and more technologically advanced upgrades - and enemies - than steambotkind has seen before.
Overall, it's fairly barebones and serves to keep the player moving, but don't expect to remember much once you've moved on.
The primary focus of the game is on the mine, split up into three sections: Archaea, The Old World, and Vectron. These worlds are procedurally generated, so no guide will help you get further down besides learning the proper techniques. Buried in similarly random locations are precious metals, limited only by your finite inventory space. These will serve as your XP and currency within the game. This overworld is split up by caves at specified depths in the mine, and these are static, unchanging challenges. This is where you'll find either good money or new upgrades to continue onwards.
Rusty is thankfully particularly mobile even without upgrades. Wall jumps and slides form the basis of basic traversal in the mines, and while he eventually gets running, high jumps and double jumps, this basic never changes. The same techniques of making mines are just as valid when facing the final boss as they are at the beginning of the game.
Aside from his trusty pickaxe, there are three meters to watch. Health is the obvious. Water fuels your special attacks and moves, from a high steam jump to a drill to a steam-powered punch. Light is a constantly dwindling resource, and once it's out, you'll be hard-pressed to see more than a silhouette of resources or enemies. Light is replenished whenever you head back to the hub world, which is fairly frequently.
At Tumbleton, you can not only replenish your light supplies automatically, but sell your precious metals for cash. Cash is simultaneously your experience meter, and the more cash you've brought overall, the more upgrades you can afford. These range from straight upgrades of more health/water/light/inventory, but occasionally there are special upgrades that make steam punches charge faster, steam jumps use less water, or retain more water from a pool.
Due to the shared cash as XP, there is rarely an opportunity to have all upgrades until close to the end of the game. There's always something else to work towards, and by the time you have it, you'll either level up and have more upgrades to choose from, or work into another cave to pick up a new upgradeable ability and start all over again.
The game stumbles a bit when it comes to other staples of the genre, such as backtracking and sequence breaking. Typically, by the time you've come across a cave, you can complete it. Once you've finished with Archaea, for instance, there will only be one reason to ever go back, and the only other reason to go back to The Old World after reaching Vectron is finding metals for a separate achievement.
Similarly, while there's an achievement dedicated to sequence breaking, it's the only sequence breaking opportunity in the game. You simply can't enter The Old World without the Drill, and you can't enter Vectron without the Fall Dampeners. Any other changes to the route would simply make things harder without actually changing the route.
If you're expecting boss fights, or really any significant combat at all, you're in for disappointment. There's exactly one boss in the entire game; the rest of combat is all about getting the timing right on the pickaxe or simply punching things enough. The primary enemy is, for all intents and purposes, the cave.
For fans of the genre, this will be a stroll in the park. The primary point of contention will be the overworld map, where the user-created tunnels may cause some problems if mined improperly. For instance, there are large, Rusty-sized rocks (and larger, Rustier-sized rocks!) that will tremble and fall if you mine underneath them. These can either block your route or, if you're underneath them, instantly kill you, one of the few credible threats in the game. Additionally, you can't jump and mine, so your upward mobility is limited. This can be particularly problematic if you mine into an open cavern and find you have no way of walljumping back up. These moments are offset by various consumables, such as ladders or teleporters that can bring you directly back to town.
Combat starts off a bit unintuitive, as the pickaxe has very short range and you'll find yourself getting hurt a bit more often than not should you not immediately get the hang of it. However, once the steam punch is acquired, the flushing sound you're hearing is the combat difficulty going down the drain.
All in all, the game may take some getting used to for beginners, but once you get going, and once you get a few upgrades, very few things will pose a serious threat.
The 2D graphics are crisp, sharp, and definitely on the more impressive end for an ID@XBOX title. The audio isn't particularly noteworthy, but there's nothing bad to say about either.
A barebones 4 of 14 achievements are related to direct story progression. Particularly thorough players will unlock 3 more for exploration. An additional 4 are related to requirements at endgame of collecting the majority of cash, orbs, not dying, and finishing under two and a half hours. The most difficult achievement requires a player to do all four in a single run. Of the remaining two, one is for sequencing breaking, and without looking at a guide, this is liable to come on a second run.
In short, the achievement list is particularly doable, with the real challenge coming from a 90+% no death speed run.
Laidback to the point of offering no challenge, SteamWorld Dig nevertheless remains a solid, competent, fun title. While veterans of the genre may be put off by the slightly more linear aspects, the well-balanced upgrades to progression mean there's always something to work towards, and give another reason to dig into this title a little deeper.