=======
Header file
=======
#ifndef _GAMESTUFF_H
#define _GAMESTUFF_H

#include "allegro.h"

// Monster function prototypes

void drawmonster(int num);
void erasemonster(int num);
void movemonster(int num);
void monsterexplode(int num);

// define the monsters
struct tagMonster
{
       int lifepoints;
       int moneyvalue;
       int walkspeed;
       int xlocation;
       int ylocation;
       bool stillalive;
       
}monsters[9];
#endif
=====
main.cpp
=====

#define ALLEGRO_STATICLINK

#include <stdlib.h>
#include "allegro.h"
#include <GameStuff.h>

int gamelevel = 1;
int CitizenCounter = 10;
int Money = 100;
bool GameOver = false;
int mx;
int my;
int mousebutton;

// Game recordkeeping functions
void UpdateCitizens()
{
    rectfill(screen,560,300,615,350,9);    
    textprintf_ex(screen, font, 580, 320, 15,9,"%d",CitizenCounter);
}
void UpdateMoney()
{
     rectfill(screen,0,440,100,480,10);
     textprintf_ex(screen,font,10,465,15,10,"Money Remaining: $%d",Money);
}

void movemonster(int n)
{
     if ((monsters[n].xlocation < 250) && (monsters[n].ylocation < 225))
     {
          monsters[n].ylocation++;
     }
     if ((monsters[n].xlocation < 250) && (monsters[n].ylocation == 225))
     {
          monsters[n].xlocation++;
     }
     if ((monsters[n].xlocation == 250) && (monsters[n].ylocation > 125))
     {
          monsters[n].ylocation--;
     }
     if ((monsters[n].xlocation < 425) && (monsters[n].ylocation == 125))
     {
          monsters[n].xlocation++;
     }
     if ((monsters[n].xlocation == 425) && (monsters[n].ylocation < 325))
     {
          monsters[n].ylocation++;
     }
     if ((monsters[n].xlocation < 530) && (monsters[n].ylocation == 325))
     {
          monsters[n].xlocation++;
     }
}

void createmonster(int n)
{
     monsters[n].xlocation = 45;
     monsters[n].ylocation = 0 - ((n - 1) * 50);
     monsters[n].moneyvalue = gamelevel;
     monsters[n].lifepoints = (gamelevel * 1.25);
     monsters[n].walkspeed = 1000;
     monsters[n].stillalive = true;     
}

void erasemonster(int n)
{
     circlefill(screen, monsters[n].xlocation, monsters[n].ylocation, 18, 6);
}

void drawmonster(int n)
{
     circlefill(screen, monsters[n].xlocation, monsters[n].ylocation, 18, 5);
}

void monsterexplode(int n)
{
     ;
}


int main()
{
    //Initialize Allegro
    allegro_init();
    
    //Initialize keyboard
    install_keyboard();
    
    //Install mouse
    install_mouse();

    //initialize video mode to 640x480
    int ret = set_gfx_mode(GFX_AUTODETECT_WINDOWED, 640, 480, 0, 0);
    if(ret != 0) {
           allegro_message(allegro_error);
           return 1;
           }

    //Make the background green
    rectfill(screen,0,0,640,480,10);
    
    //Draw the pathway
    rectfill(screen,0,0,70,200,6);
    rectfill(screen,0,200,230,250,6);
    rectfill(screen,230,100,275,250,6);
    rectfill(screen,275,100,400,150,6);
    rectfill(screen,400,100,450,350,6);
    rectfill(screen,450,300,550,350,6);
    
    //Draw the castle
    rectfill(screen,550,290,625,365,0);
    circlefill(screen,545,285,18,0);
    circlefill(screen,545,370,18,0);
    circlefill(screen,630,285,18,0);
    circlefill(screen,630,370,18,0);
    
    //Draw the rectangle that will contain the citizens
    rectfill(screen,560,300,615,350,9);
    
    //Draw the tower build section of the screen
    rectfill(screen,0,400,200,435,9);
    textprintf_ex(screen,font,5,415,15,9,"Click this area");
    textprintf_ex(screen,font,5,425,15,9,"to build a tower");
    
    
    //Draw the initial citizen total
    UpdateCitizens();
    
    //Draw the starting money
    UpdateMoney();
    //Cause the program to show the mouse
    show_mouse(screen);

    while(!GameOver)
    {
    //This is the main game loop
    
         //Create the monsters
         for(int x = 0; x < 10; x++)
         {
                 createmonster(x);
         }
         
         //Internal game loop to handle monster movement, shooting, etc.
         for(int walkcount = 0; walkcount < 1500; walkcount ++)
         {
//Did the player click on 'Build a tower'?
          mx = mouse_x;
          my = mouse_y;
          if((mx < 200) && (mx > 0) && (my < 435) && (my > 400))
          {
          mousebutton = (mouse_b & 1);
          if(mousebutton)
          {
               textprintf_ex(screen,font,5,415,9,9,"Click this area");
               textprintf_ex(screen,font,5,425,9,9,"to build a tower");
               textprintf_ex(screen,font,5,415,15,9,"Click any valid");
               textprintf_ex(screen,font,5,425,15,9,"area to build a tower");
          }
          }                 
                 rest(5);
                 //Move the monsters
                 for (int x = 0; x < 10; x++)
                 {
                     
                     if (monsters[x].stillalive)
                     {
                          erasemonster(x);
                          movemonster(x);
                          drawmonster(x);
                          if (monsters[x].xlocation > 529)
                          {
                               erasemonster(x);
                               monsters[x].stillalive = false;
                               monsters[x].xlocation = 0;
                               monsters[x].ylocation = 0;
                               CitizenCounter--;
                               UpdateCitizens();
                               if (CitizenCounter == 0)
                               {
                                    while(!key[KEY_ESC])
                                    {
                                         textprintf_ex(screen,font,310,240,15,10,"GAME OVER!! Press ESCape to Exit");
                                    }
                               }
                          }
                      }
                  }
         }
     }
     //end program
     allegro_exit();
     return 0;
}
END_OF_MAIN();