You're slowly laying bricks. It's not just an ordinary choice. The choices in the bricklaying process are shown in the form of concrete (heh heh) poetry. Still, after a while, frustration starts to build, as shown in the concrete poem you are slowly writing through your choices. The idea and overall effect is pretty cool.
I played this game on mobile, so I might have missed that last surprise mentioned in the description. Anyway, as per recommendation, I played on landscape mode.