The best ideas, of course, are the simplest ones and Vorble's core idea is deliciously simple. It's what developer MegaTree calls a "mind sport", a three-dimensional spin on chequers with maybe a bit of backgammon and dominoes thrown in. Play takes place on a sphere made up of geometric faces - some pentagons, some hexagons. It's like a football, a fact the tutorial handily illustrates by temporarily changing the colour of the faces to black and white.
Changing the colour is also what you'll be trying to do, by placing pegs on these five and six-sided panels. Once a panel has as many pegs as it does sides, a cascade is triggered and those pegs are sent to the surrounding panels, leaving the original panel clear. If your opponent has placed a peg on a panel, the only way to take it off them is by catching it in a cascade. As it's played on a sphere, there's no boundary to the game and triggering chains of cascades that keep going around the play area is where the big scores lie, and as the "board" starts to fill up with pegs, the potential for a game-winning avalanche increases.
It's one of those ideas that seems so compact and perfectly self-contained, and so obvious once you've seen it in action, that you wonder why nobody did it before.