Machines is a theater-like game for any size group of theater-like people.
One person begins the machine by walking into the center of the circle and starting a repetitive motion, accompanied by a sound. As with all repetitive, sound-accompanied motions, it is repeated, and repeated, and, um, repeated.
Actually, two people can start, making two motions (somehow related, maybe) with two sounds, repetitively.
Then, when so moved, someone else joins a sound-cum-motion. And so on and so on until everyone is involved.
Machines can be purpose-built. That is, the goal can be to create a paper-clip-making machine or a merry-go-round turning machine or a, well, you get the point.
Machines can be asked to increase speed until collapse or disintegration or mayhem ensues. In like manner, machines can be asked to slow down until overtaken by stillness or sleep.
There is no point to this game. Please keep it that way.