What's interesting about Boomshine is they way it both fits into and defies expectations about "the game," that is, the elements that (pace Wittgenstein) all games actually do share, that makes them, in esse, games.
It's a little one-click game in which a number of colored dots wander about the screen, in a Newtonian way, bouncing off the edge of the screen. Once each level, you may click anywhere; doing so creates a bubble that quickly blows up to a fixed size, and lasts in duration for a few seconds. During that duration, any dots that encounter the bubble likewise blow up into bubbles -- and any dots that encounter this bubble then likewise cause dots to bubble up as well. In principle, you can clear the screen through a chain-reaction of bubbles; in practice, this rarely happens.
