I have a problem with my first processing project, which is a small game. Try it out yourself, its somewhat working right now, but Im missing some features im not sure how to add, specifically:

1) How do I go about making and endstate gameover when boxes reach screen width and have it show score, plus press spacebar to start over?

2) How do I fix it so the mouse cannot be held down and just moved over the objects but you have to actively click each object?

I know width/height of the sketch are kind of wierd, but its values determined by our teacher, not of my own choosing.

1. // Declare four Circle objects as global variables
   Circle myCircle1;
   Circle myCircle2;
   Circle myCircle3;
   Circle myCircle4;
   
   // Declare eight Box objects as global variables
   Box myBox1;
   Box myBox2;
   Box myBox3;
   Box myBox4;
   Box myBox5;
   Box myBox6;
   Box myBox7;
   Box myBox8;
   
   void setup() {
    
   size(800,100);  // Sketch x and y size
   frameRate(60);  // Sketch framerate
   
   // Initialize Circle objects by calling the Circle constructor
   myCircle1 = new Circle(color(255,0,0),random(100,700),random(10,90),2,2);
   myCircle2 = new Circle(color(255,80,0),random(100,700),random(10,90),2,2);
   myCircle3 = new Circle(color(255,160,0),random(100,700),random(10,90),2,2);
   myCircle4 = new Circle(color(255,240,0),random(100,700),random(10,90),2,2);
   
   // Initialize Box objects by calling the Box constructor
   myBox1 = new Box(color(255,40,0),random(5,10),random(15,85),15,15);
   myBox2 = new Box(color(255,120,0),random(5,10),random(15,85),15,15);
   myBox3 = new Box(color(255,200,0),random(5,10),random(15,85),15,15);
   myBox4 = new Box(color(255,40,0),random(5,10),random(15,85),15,15);
   myBox5 = new Box(color(255,200,0),random(5,10),random(15,85),15,15);
   myBox6 = new Box(color(255,120,0),random(5,10),random(15,85),15,15);
   myBox7 = new Box(color(255,40,0),random(5,10),random(15,85),15,15);
   myBox8 = new Box(color(255,200,0),random(5,10),random(15,85),15,15);
   }
   
   void draw() {
   cursor(CROSS);        // Replace the normal cursor with a cross
   background(0,0,0);    // Set background to black
   
    
   fill(0,255,0);            // Make the score count green
   text("Score:",720,20);    // Place score text in upper right corner
   text(score,760,20);       // Place score integer next to score text in upper right corner
   
   // Draw green text in upper left corner after 0.5 seconds
   // After eight seconds make the text go away again
   if (millis() > 500 && millis() < 8000){
   fill(0,255,0);
   text("Shoot the circles before they grow too big!",10,20);
   }
   
   // Draw green text in the upper left corner after 9.5 seconds
   // After 17 seconds make the text go away again
   if (millis() > 9500 && millis() < 17000){
   fill(0,255,0);
   text("Shoot the boxes before they reach the other side!",10,20);
   }
   
   // Spawm the boxes and make them move
   // Each Box Object calls the object method using dot syntax
   // Interval between each box spawn is 10 seconds
   // Done by checking how long since applet started
   float boxm = millis();
   if (boxm > 10000) {
   myBox1.boxmove();
   myBox1.boxdisplay();
   }
   if (boxm > 20000) {
   myBox2.boxmove();
   myBox2.boxdisplay();
   }
   if (boxm > 30000) {
   myBox3.boxmove();
   myBox3.boxdisplay();
   }
   if (boxm > 40000) {
   myBox4.boxmove();
   myBox4.boxdisplay();
   }
   if (boxm > 50000) {
   myBox5.boxmove();
   myBox5.boxdisplay();
   }
   if (boxm > 60000) {
   myBox6.boxmove();
   myBox6.boxdisplay();
   }
   if (boxm > 70000) {
   myBox7.boxmove();
   myBox7.boxdisplay();
   }
   if (boxm > 80000) {
   myBox8.boxmove();
   myBox8.boxdisplay();
   }
   
   // Spawn circles and make them grow
   // Each Circle Object calls the object method using dot syntax
   // Time since applet start checked to make Circles spawn at specific time intervals
   float m = millis();
   if (m > 2500) {
   myCircle1.grow();
   myCircle1.display();
   }
   if (m > 5000) {
   myCircle2.grow();
   myCircle2.display();
   }
   if (m > 7500) {
   myCircle3.grow();
   myCircle3.display();
   }
   if (m > 10000) {
   myCircle4.grow();
   myCircle4.display();
   }
   
   
   if (mousePressed){
   // Create variables for the distance between mouse position and the position of the circles and boxes with cool dox syntax
   float distance1 = dist(mouseX, mouseY, myCircle1.xpos, myCircle1.ypos);
   float distance2 = dist(mouseX, mouseY, myCircle2.xpos, myCircle2.ypos);
   float distance3 = dist(mouseX, mouseY, myCircle3.xpos, myCircle3.ypos);
   float distance4 = dist(mouseX, mouseY, myCircle4.xpos, myCircle4.ypos);
   
   float bdist1 = dist(mouseX, mouseY, myBox1.xpos, myBox1.ypos);
   float bdist2 = dist(mouseX, mouseY, myBox2.xpos, myBox2.ypos);
   float bdist3 = dist(mouseX, mouseY, myBox3.xpos, myBox3.ypos);
   float bdist4 = dist(mouseX, mouseY, myBox4.xpos, myBox4.ypos);
   float bdist5 = dist(mouseX, mouseY, myBox5.xpos, myBox5.ypos);
   float bdist6 = dist(mouseX, mouseY, myBox6.xpos, myBox6.ypos);
   float bdist7 = dist(mouseX, mouseY, myBox7.xpos, myBox7.ypos);
   float bdist8 = dist(mouseX, mouseY, myBox8.xpos, myBox8.ypos);
   
   // If mouse is within the boxes when clicked reset the boxes to their original values in void Setup and add 1 to score integer
   if (bdist1 < myBox1.xsize/2){
   myBox1 = new Box(color(255,40,0),random(5,10),random(15,85),15,15);
   score = score + 1;
   }
   if (bdist2 < myBox2.xsize/2){
   myBox2 = new Box(color(255,40,0),random(5,10),random(15,85),15,15);
   score = score + 1;
   }
   if (bdist3 < myBox3.xsize/2){
   myBox3 = new Box(color(255,40,0),random(5,10),random(15,85),15,15);
   score = score + 1;
   }
   if (bdist4 < myBox4.xsize/2){
   myBox4 = new Box(color(255,40,0),random(5,10),random(15,85),15,15);
   score = score + 1;
   }
   if (bdist5 < myBox5.xsize/2){
   myBox5 = new Box(color(255,40,0),random(5,10),random(15,85),15,15);
   score = score + 1;
   }
   if (bdist6 < myBox6.xsize/2){
   myBox6 = new Box(color(255,40,0),random(5,10),random(15,85),15,15);
   score = score + 1;
   }
   if (bdist7 < myBox7.xsize/2){
   myBox7 = new Box(color(255,40,0),random(5,10),random(15,85),15,15);
   score = score + 1;
   }
   if (bdist8 < myBox8.xsize/2){
   myBox8 = new Box(color(255,40,0),random(5,10),random(15,85),15,15);
   score = score + 1;
   }
   
   // If mouse is within the circles when clicked reset the circles to their original values in void Setup and add 1 to score integer
   if (distance1 < myCircle1.xgrowth/2){
   myCircle1 = new Circle(color(255,0,0),random(100,700),random(10,90),2,2);
   score = score + 1;
   }
   if (distance2 < myCircle2.xgrowth/2){
   myCircle2 = new Circle(color(255,80,0),random(100,700),random(10,90),2,2);
   score = score + 1;
   }
   if (distance3 < myCircle3.xgrowth/2){
   myCircle3 = new Circle(color(255,160,0),random(100,700),random(10,90),2,2);
   score = score + 1;
   }
   if (distance4 < myCircle4.xgrowth/2){
   myCircle4 = new Circle(color(255,240,0),random(100,700),random(10,90),2,2);
   score = score + 1;
   }
   }
   }
   
   // Variable to keep count of the score initialized. Integer, not float, as we don't want decimal numbers displayed
   int score = 0;
   
   // Define the Circle class - Below the rest of the program - Note: need to put in new tab, keeps fucking it up though
   class Circle{
   // Variables for Circle class
   color c;
   float xpos;
   float ypos;
   float xgrowth;
   float ygrowth;
   // Constructor for the Circle class
   Circle(color tempC, float tempXpos, float tempYpos, float tempXgrowth, float tempYgrowth) {
   c = tempC;
   xpos = tempXpos;
   ypos = tempYpos;
   xgrowth = tempXgrowth;
   ygrowth = tempYgrowth;
   }
   
   void display() {
   // Ellipse function to actually draw the things
   fill(c);
   ellipse(xpos,ypos,xgrowth,ygrowth);
   }
   
   void grow() {
   // Function to make the Circle grow and pop back to small size when it gets over 300 high as well as assign new random x and y values for respawn
   xgrowth = xgrowth +0.5;
   ygrowth = ygrowth +0.5;
   if (xgrowth > 200) {
   score = score -10;
   xpos = random(100,700);
   ypos = random(10,90);
   xgrowth = 0.5;
   ygrowth = 0.5;
   }
   }
   }
   
   // Define the Box class - Below the rest of the program - Note: need to put in new tab, keeps fucking it up though
   class Box{
   // Variables for Box class
   color c;
   float xpos;
   float ypos;
   float xsize;
   float ysize;
   // Constructor for the Box class
   Box(color tempC, float tempXpos, float tempYpos, float tempXsize, float tempYsize) {
   c = tempC;
   xpos = tempXpos;
   ypos = tempYpos;
   xsize = tempXsize;
   ysize = tempYsize;
   }
   
   void boxdisplay() {
   // Rect function to actually draw the things, rectmode center important so clicking outside the boxes won't work
   fill(c);
   rectMode(CENTER);
   rect(xpos,ypos,xsize,ysize);
   }
   
   void boxmove() {
   // Function to make the Box move and pop back to start when it goes beyond width as well as assign new random x and y values for respawn
   xpos = xpos +0.5;
   if (xpos > 800) {
   xpos = random(5,10);
   ypos = random(15,85);
   xsize = 15;
   ysize = 15;
   }
   }
   }