This simplistic simulation is more built for entertainment than realism—there aren't even food dishes. The cat wanders around, meowing occasionally. You can click on the background to call him, and click on him to make him meow. By clicking and dragging on him you can move him around. The brush and the toy can also be moved by clicking and dragging. When the toy touches the cat, he will swat at it. If he touches the brush, he will lay down and make a different meow. Sometimes, even after the brush is removed, he will continue, so just distract him with the toy or call him to make him stop. When he begins to get tired, he will yawn occasionally, and then stay yawning and meow until you put him in his bed (the green thing), which is also moveable.
I may make more upgraded versions of this later. Have fun!