writing something in C from scratch for the first time

cat-game.c

// make cat-game and ./cat-game to play, macOS

#include <stdio.h>
#include <stdlib.h>
#include <string.h> 
#include <time.h>

// adds ability to pause 
void nsleep(long us)
{
  struct timespec snooze;
  snooze.tv_sec = us / (1000 * 1000);
  snooze.tv_nsec = (us % (1000 * 1000)) * 1000;
  nanosleep(&snooze, NULL);
}

// this part mostly defines different kinds of ASCII cats 
// it might be easier to jump to the bottom and move up to read the code!

void draw_winner()
{
 printf("               ________________                 \n");
 printf("         _|::|| Purrrr...      |                \n");
 printf("      _|::|   |       You win! |                \n");
 printf("     |::|     |________________|                \n");
 printf("                               |        /\\**/\\ \n");
 printf("                               |       _( ^_^ ) \n");
 printf("                               |  (_//   u--u)  \n");
 printf("                                 \\==(  ___||)   \n");
 printf("                             ,dP /b/=( /P /b\\  \n");
 printf("                             |8 || 8\\=== || 8  \n");
 printf("                             'b,  ,P  'b,  ,P   \n");
}
 
void draw_loser()
{
  printf("               ________________                 \n");
  printf("         _|::|| Grrrrr...      |                \n");
  printf("      _|::|   |       Go away! |                \n");
  printf("     |::|     |________________|                \n");
  printf("                               |        /\\**/\\ \n");
  printf("                               |       _( >_< ) \n");
  printf("                               |  (_//   u--u)  \n");
  printf("                                 \\==(  ___||)   \n");
  printf("                             ,dP /b/=( /P /b\\  \n");
  printf("                             |8 || 8\\=== || 8  \n");
  printf("                             'b,  ,P  'b,  ,P   \n");
}

void clear_screen()
{
  nsleep(800000);
  printf("- - - - - - - - - -\n");
  printf("       \\ | / \n");
  printf("     '-.;;;.-' \n");
  printf("    -==;;;;;==- \n");
  printf("     .-';;;'-. \n");
  printf("       / | \\ \n");
  printf("- - - - - - - - - -\n\n");
  nsleep(400000);
  printf(". \n");
  nsleep(400000);
  printf(". . \n");
  nsleep(400000);
  printf(". . .\n");
  nsleep(800000);
}

void fancy_cat()
{
  printf(" /\\-/\\  \n");
  printf("(=^Y^=)\n");
  printf(" (>o<) \n");
}

void wary_cat()
{
  printf("   |\\=/| \n");
  printf("   /6 6\\   _ \n");
  printf("  =\\_Y_/= (( \n");
  printf("   / ^ \\   ))  \n");
  printf("  /| | |\\ // \n");
  printf(" ( | | | )/ \n");
  printf("   `"" ""` \n");
}

void tiny_cat()
{
  printf(" \\    /\\ \n");
  printf("  )  ( ')     \n");
  printf(" (  /  ) \n");
  printf("  X     \\(__)| \n");
}

void long_cat()
{
  printf("     /\\-/\\  \n");
  printf("    /o o  \\                                                        _  \n");
  printf("   =\\ Y  =/-~~~~~~-,______________________________________________/ )  \n");
  printf("     '^--'          _______________________________________________/  \n");
  printf("       \\           /  \n");
  printf("       ||  |---'\\  \\  \n");
  printf("      (_(__|   ((__|  \n");
}

void curious_cat()
{
  printf(" /\\___/\\ \n");
  printf("( o   o ) \n");
  printf("(  =^=  ) \n");
  printf("(        ) \n");
  printf("(         ) \n");
  printf("(          ))))))))))) \n");
}

void hissing_cat()
{
  printf("               _ \n ");
  nsleep(100000);
  printf("               \\`\\ \n ");
  nsleep(100000);
  printf("     /./././.   | | \n ");
  nsleep(100000);
  printf("   /        `/. | | \n ");
  nsleep(100000);
  printf("  /     __    `/'/' \n ");
  nsleep(100000);
  printf("/\\__/\\ /'  `\\    / \n ");
  nsleep(100000);
  printf("| O  O |      `.,.| \n ");
  nsleep(100000);
  printf(" \\vvvv/        |||| \n ");
  nsleep(100000);
  printf(" ||||        |||| \n ");
  nsleep(100000);
  printf(" ||||        |||| \n ");
  nsleep(100000);
  printf(" `'`'        `'`' \n ");
}

void game_intro()
{
  printf("Welcome to Cat Game\n");
  printf("The goal of this game is to pet a cat.\n");
  printf("Every day, you eat lunch outside and encounter many cats.\n");
  printf("But they run away when you try to pet them.\n");
  printf("Can you win the affection of a cat?\n");
  printf("If you want to exit the game at any time, type 0\n");
  printf("You have one week (7 days) to win.\n\n");
  printf("OK, let's not waste time! \n");  
}

void game_options()
{
  printf("1. Pick up.\n");
  printf("2. Hold treat.\n");
  printf("3. Do nothing.\n");
  printf("4. Pet! On the head.\n");
  printf("5. Pet! On the tail.\n");
  printf("6. Pet! On the back.\n");
}

// bulk of operations begins 

void final_day(choice)
{
  clear_screen();
  if (choice == 4){
    draw_winner();
  } else {
    draw_loser();
  }
}

void perform_action(choice,count)
{
  if (count == 7) {
    final_day(choice);
  } else {
    switch(choice) {
      case 1:
        printf("You picked... 1. Pick up.\n");
        break;
      case 2:    
        printf("You picked... 2. Hold treat.\n");
        break;
      case 3:    
        printf("You picked... 3. Do nothing.\n");
        break;
      case 4:
        printf("You picked... 4. Pet! On the head.\n");
        printf("\n\n HISSSSSSSSSSSSSSSS!!!");
        break;
      case 5:
        printf("You picked... 5. Pet! On the tail.\n");
        printf("\n\n HISSSSSSSSSSSSSSSS!!!");
        break;
      case 6:
        printf("You picked... 6. Pet! On the back.\n");
        printf("\n\n HISSSSSSSSSSSSSSSS!!!");
        break;
      default:
        printf("You picked... ???. Do nothing.\n");
        break;
     }
     hissing_cat();
     printf("\n The cat ran away! Better luck tomorrow.\n"); 
   }
}

void get_cat() 
{  
  srand(time(NULL));
  int randomnumber;
  randomnumber = rand() % 6;
  switch(randomnumber) {
    case 1:
      fancy_cat();
      break;
    case 2:
      tiny_cat();
      break;
    case 3:
      curious_cat();
      break;
    case 4:
      long_cat();
      break;
    case 5:
      wary_cat();
      break;
    default:
      wary_cat();
   }
   printf("\n");
}

void check_choice(count)
{
  char buffer[10];
  while (1) {
    fgets(buffer, 10, stdin);
    int choice = buffer[0] - '0';
    if (choice == 0){
      exit(0);
    }
    if (choice <= 6 && choice >= 0){
      printf("\n");
      perform_action(choice,count);  
      break;
    } 
    else
      printf("Must be a number between 1-6 to continue. To quit, type 0.\nYour choice: ");
  } 
}

const char* game(int user)
{
  game_intro();
  int count = 0;
  do 
  { 
    count++;   
    clear_screen();
    printf("- - - - - - - - - -\nDay %d out of 7",count);
    printf("\n- - - - - - - - - -\nA new day! Here comes a cat...\n\n");
  
    get_cat();
    game_options();
    printf("\nWhatcha gonna do? Pick a number.\n");
    
    if (count == 7){
      printf("\n\n\nLast chance!!!! Choose wisely. It may very well be that nothing has mattered up until this point...\n\n\n"); 
    }
    
    printf("Your choice: ");
    check_choice(count);

  } while (count < 7);
  exit(0);
}
 
// start it up!!!
int main()
{
 int begin = 0;
 while (1) printf("%s", game(begin = !begin));
 return 0;
}