I picked this up awhile ago, and only ended up playing a bit of it before writing it off. Recently though, I decided to play it again, and ended up playing through to completion in one sitting.
SteamWorld Dig is a great little arcade-platformer. You play the role of Rusty, a robot cowboy/prospector that has come to town to find out more about his uncle. Equipped with only a pickaxe, you begin to excavate the depths below Tumbleton.
At it’s heart SteamWorld Dig is a run-jump-and-dig platforming/collection game. More advanced platforming mechanics are introduced throughout the "dig", through mini-caves scattered within the main shaft. Mining and selling the ores you find exploring is the main mechanic to buy upgrades. I found myself a little frustrated at times with my purchases being non-optimal, but there is probably a science to the upgrades that would make the gameplay feel a bit more rewarding.
Exploring otherwise felt fun and engaging. All the ores to be mined brought out the completionist side in me. The “natural” obstacles were easily overcome with the correct upgrades, but sometimes just ended up requiring a bit more scavenging be done in order to purchase the correct upgrade so that you could continue.
The art-style and characters are fun and surface-level interesting. The story is basically there to serve a glue for the game to make sense — it isn’t really necessary, but doesn’t get in the way if you just want to dig.
Overall, I’d recommend this game as it provides enough of the fun platforming and resource collection aspects without being too hard on you when you make a poor decision in the upgrade paths. Would play again.