I frame my iterations as "releases" I guess, which is a bit different than, say, how minecraft does it. I suppose there's a line there, I'm just not sure where it is. At least one panel of judges thinks I crossed it.
But that is beside the point.
Even if you consider some of my games sequels to others (eg: Crab Attack 1, 2, and 3), each should be judged solely by itself, and not framing it against it's predecessors. IMHO opinion, of course.