It's a legitimate question. Am I really just making an involved fangame of Calvin and Hobbes? Nope.
Cosmo is rapidly blurring into a generic tow-headed hellion, and that's good, and Hobbes is absent (or IS he dun dun DUN) so it has a world of its own.
To an extent the project definitely is a fangame of Spaceman Spiff, a Spaceman Spiff computer game, yeah. But it's a lot more than that. The Watterson stuff itself was an excuse for him to try and break free of the toxic narrowness of the shall we say "unsentimental" world of insitutionalised art prostitution in the newspaper strip industry. But by the time he'd illustrated a Krazy Kat background as a planet or done a loving panel of a dinosaur or old Alex Raymond style pulp sci fi adventures it sort of wound up fast, format and inclination and even skill permitting. In other words, Bill Watterson's lushest Spaceman Spiff stuff still ba-doom tishes off at the last panel and that's that, it never sustained a narrative. Part of the fun and even mystique of Calvin's private worlds is that there are ever only glimpses of them. That's great, but it also let the author off the hook, because he could endlessly set it up, only to abandon it instead of following the thought through for a page, or even a whole comicbook. Compare to classic Peanuts at the height of Shultz's power. Complete narratives, with sparser details, or almost no details.