New features for Processing game/desk accessory

Question

I have written a simple desk accessory in Proccessing called Trip, you can see it below. It is working, but it is very simple, and needs more features.

import processing.pdf.*;

PImage tardis;
int flash = 0;

void setup() {
  size(256, 256);
  frame.setResizable(true);
  tardis = loadImage("TARDIS1.jpg");
  beginRecord(PDF, "trip.pdf");
  background(random(100), random(100), random(100));
  randomSeed(299792458);
}
void draw() {
  stroke(random(100), random(100), random(100));
  line(random(width), random(height), mouseX, mouseY);
  if (flash == 1) {
    background(random(100), random(100), random(100));
  }
}
void keyPressed() {
  if (key == 's') {
    endRecord();
    exit();
  }
  else if (key == 'q') {
    exit();
  }
  else if (key == 'b') {
    background(random(100), random(100), random(100));
  }
  else if (key == 't') {
    image(tardis ,0 ,0, width, height);
  }
  else if (key == 'f') {
    if (flash == 0) {
      flash = 1;
    }
    else if (flash == 1) {
      flash = 0;
    }
  }
}

I would appreciate any new ideas for features, particularly Easter egg-style secret features.

Answer 1

How about something where if you change the background to a particular color, something cool happens?

Like if it turns full black,(0,0,0), it causes an image to pop up on screen.