Well, it's exactly just more of the same, but this time with really bad music. It ranges from forgettable to town theme, which sounds like very dirty disk (it means vinyl) with Aerosmith - Dream On is stuck on loop in tiny pathephone (different thing), which have been sat on.
The game takes place some time after the end of the first one and before the Steamword Heist. Which both neatly ties the whole Steamworld universe, even the Outsider DLC for Steamworld Heist, and makes said DLC even more aggravating, rendering the comparison with Mass Effect 3: From Ashes even more on point. Also i'm not a fan of the direction they took with humies, it was too tropey and felt like so called "punching down". And if they tried to make complicatedly motivated drama with post-modernistic recontextualization of your actions in the first game they didn't really succeeded at that.
In it's core the gameplay is still good and feels like streamlined single adventure module for terraria (or Starbound, with its puzzles) with post-metroid level-design decisions. Game doesn't restrict your tools and there is a lot of sequence breaking possible. New upgrade and ability customization system is very nice and allows some neat synergies. It compares to Steamworld Dig like Diablo 2 to Diablo — first is tight and neat single dungeon experience, the second is sprawling adventure in several thematic zones.
For some reason they turned Dot into a crazy frog and she not only looks like it but also animated like it. The other boots look like always, but main character in motion looks very uncanny as if it's cell-shaded 3D model or morphed animation, instead of the doll one. Overall main character looks very unpleasant, and considering that you stuck with it and it's the main focus of your sight — it's kind of an issue.
Game works fine with UWS UHD Surround, but limits the view instead of increasing it. Still there is an option to use pillarboxing to fix that.
Overall, if you want more Steamworld Dig — it is one and good at that. Also it's one of the best games of the year, which says more about the year than about this game.