It turns out Mojo Bones actually considered adding permadeath to Impact Winter as a launch feature, but ditched it as "it didn't fit the game's length". However, this has now been introduced four months after launch as an alternative challenge in the form of a new Expert game mode. In other words, not only do you have to survive with Jacob for 30 days - now the "survive" part is literal, as you only have one "life", making the experience even tougher.
The latest update also brings a bunch of fixes in terms of performance (framerate, load times, collisions) and the highly-requested expanded control features with the mouse+keyboard combo.
Now the game looks and plays better (and more challenging if you want) on PC. Meanwhile, Mojo Bones are making preparations to launch on Xbox One and PS4 before the year's end.