but basically it was explorative coding: start with a circle, OK, let's move the circle around, what's next? More circles, OK what happens if the intersect ... And so on.
timeline wise bubbles was first (osmosis is the great-grandfather), but as always: ideas are in the air, forked, replicated, mutated, pivoted, and then taken multiplayer (agar.io is genius, love it)
Your game "Bubbles" reminds me of Osmos (http://www.osmos-game.com/), has it inspired you?