But work on that second game wasn't done in downtime, while work on SiS continued... it was done instead of working on SiS!
So yes, SiS was affected by Wildman preparing for second project. Especially since that was where the focus was during month of December.
Sadly, I can't think of a single example of developer starting to work on a second, unrelated game (not sequel) before completing first game where both games were not negativelly affected and at least one if not both end up abandoned...
In what way
specifically do you think SiS will be negatively affected by
Wildman Dev's preliminary work on his second game project? What is the average timespan between update releases of SiS? What is the range of timespans (shortest to longest) between update releases of SiS? If the timespan between the last update and the coming update is greater than the average timespan but well short of the longest timespan, is that really a problem (i.e., evidence of having been "negatively affected")? What is your honest estimate of the probability of
Wildman Dev abandoning SiS due to working on a second game project?
EVERYTHING
Wildman Dev does when he's not working on Stranded In Space -- eating, sleeping, taking a dump, working a "day job" IRL, etc. -- technically delays the release of the next update, as does work on a second project (There's your lesson for the day on the concept of Opportunity Cost... You're welcome.). However, unless there is empirical evidence that any of that is materially compromising the quality and/or frequency of SiS updates and overall SiS game progress, then it's not worth getting one's knickers in a knot over, IMO.