This game I just got for my Birthday two days ago, and I thought I'd make a topic about it.
It's called
Steamworld Dig.
Basically you play as a Steampunk mining robot who inherits a massive mine from his relative, and goes to dig down and find whatever treasures are down there. Along the way, he comes across some very unexpected structures and gadget upgrades, and finds out as he digs deeper that there may be more to his old relative than he thought. Also, it takes place in some sort of Post-Apocalyptic society where humans now live underground after a nuclear war, and Steampunk robots now have started a recovering society on the surface there.
It plays like a cross between Dig Dug and a Metroidvania style game. Like you have to dig down to find items and watch out for enemies, which you can kill by making rocks fall on them or by using a pickaxe, but as you venture down, you find various upgrades in side tunnels. Also you have to pay attention to how you dig, so that you have a means to get back to the surface later. You also collect ore to sell at the surface, and use the proceeds to buy new upgrades to your equipment, which are needed as you get down further. There are also things like some of your Steam-powered gadgets require water to use which you fill up by standing in pools of water in the caves, secret areas, and more.
Also, it has a sequel which I have yet to play, but there is a
Steamworld Dig 2. The game also takes place in the same universe as
Steamworld Heist turn-based strategy games, which I heard this is a prequel to.