Here’s a minimalistic 1D Pong game from Vagrearg:

How little do you need for a game
An exercise in futility. That is what many would call this endeavor. How few elements (signifiers and affordances) do you need to not only recognize a game for what it is, but also are able to play it?
It turns out that you only need very little to do very much.

Project info at vagrearg.org.