SteamWorld Dig 2

A big step up from the first SteamWorld Dig, which was already a very fun game. Unlike its predecessor, which had a randomly generated world (except the puzzle rooms), this game has a huge, fully designed game world, filled with enemy encounters, puzzles, and lots of secrets. The game follows the familiar formula of digging out treasure to sell, and earn money to buy upgrades, which enables you to dig deeper and explore new areas. Some upgrades are locked away behind difficult challenges, and others require collectible cogs, which can be distributed freely for a bit of customization to your gameplay.
The story ties into the SteamWorld universe, and follows the side-character Dorothy from the previous SteamWorld Dig game. It might therefore be a good idea to have played the first game, if you want to dig into the lore of the games. However, I think the game can be enjoyed on its own as well, since I enjoyed the story a lot without remembering much of the first game.
As usual, the SteamWorld games work great on Linux, and I hope to see another Dig game, as these are my favorites of the SteamWorld series.

Fun game, similar to Steamworld Dig 1.
The character grows stronger over time, gets cool abilities. Fighting isn't hard. Music and sound effects are OK.
Some parts seem to be added just for inflating play time for dedicated players (some achievements and trials).
Overall: simple, fun, polished game. Easy to beat, hard to complete (100% achievements).

If you ever played Motherload as a kid, you'll love this.

It's a really well crafted metroidvania. The controls feel good, the mechanics are fun and distributed at a decent pace. Difficulty is around the level of "fun challenge". Not super hard, but enjoyable. Doesn't outstay its welcome.
It's just a goodass game.

I loved the first steamworld dig, and this sequel is better in every way, wonderful, highly recommended.

Steamworld Dig 2, the successor to one of the most awesome indie games of the last couple of years makes everything better than its predecessor. Better handling, higher difficulty, more biomes, some puzzles, boss fights, more dialogue, more whacky characters, more distinguished art design and a polish of the already great mechanics of the original game.
Steamworld Dig 2 has a truly great flow when it comes to whacking away rocks and dirt while collecting all the shinies.
Content wise it can a very long or a very short game, depending on playstyle, but either case it is absolutely worth its asking price. While there's no true reason to replay this apart from challenge achievements, it remains a lot of fun even in subsequent playthroughs.

Great game. The basic gameplay loop is digging for minerals, which you then spend on upgrades that help you dig deeper and hold more resources. Additionally, the map is peppered with small dungeons that either give you talent points or metroidvania-style upgrades like a hookshot or jumpjets when you finish them. This game is absolutely worth your time.