A "one button" game I worked on in 2013 to experiment with a whole mess of ideas. Your character constantly walked forward and to the left, circling endlessly if left unattented. By holding down the single button, he changed direction to walk forward and to the right instead. The aim was to alternate button presses to make unsteady progress forward, dodging various obstacles to make your way home.
The game was under development using Scirra's Construct 2 engine for ease of multiplatform development, and even at an early stage featured some clever visual flourishes like randomly-generated flowerbeds and gentle camera swaying to emphasise the player character's inebriated nature.
I intend on revisiting this project in the future. Stay tuned!