That the game was Microids' (the
true Microids') swan song has a lot to do with the abrupt ending; they simply didn't have the resources available to finish the game as originally intended. Does it excuse the shameless cliffhanger entirely? No, but regardless, Still Life
is a classic to me, one of my top games of all time on any platform.
The so-called "sequel" was destined to fail - or at least to disappoint - from the start: a new (and largely inexperienced) team, a clunky 3D engine in place of the gorgeous pre-rendered backdrops, and the high standards set by the original saw to that. As for Art of Murder, what I played of it seemed to just be going through the motions, in places; certainly far from terrible, but nothing spectacular. But again, I haven't completed it, and to each their own.

(Though it goes without saying that AoM is definitely a better produced game than SL2, even half-played!)