Making a Platformer in GameMaker - Part 2 - Wall Jumps, Enemies, Checkpoints, and Combat

Introduction

In this tutorial, we will explore how to enhance your platformer game in GameMaker by implementing wall jumps, enemies, checkpoints, and combat mechanics. This guide is part of a six-part series, aimed at teaching you essential game development techniques while using relatively simple code. By the end of this tutorial, you will have a more interactive and engaging gameplay experience.

Step 1: Setting Up Wall Jumps

Wall jumps allow your character to jump off walls, adding a new dynamic to your gameplay.

• Create Wall Jump Variables:

  • In your player object, add variables to track whether the player is touching a wall and the jump count.

  wall_touching = false;
  jump_count = 0;
  

• Detect Wall Collision:

  • In the player's step event, check for collisions with walls.

  if (place_meeting(x + hspeed, y, obj_wall)) {
      wall_touching = true;
  } else {
      wall_touching = false;
  }
  

• Implement Wall Jump Logic:

  • Modify the jump code to allow jumping off walls when the player presses the jump key.

  if (wall_touching && jump_count < 2 && keyboard_check_pressed(vk_space)) {
      vspeed = -jump_height;  // Set a negative vertical speed for jumping
      jump_count++;
  }
  

• Reset Jump Count:

  • Reset the jump count when the player lands on the ground.

  if (place_meeting(x, y + 1, obj_ground)) {
      jump_count = 0;
  }
  

Step 2: Adding Enemies

Enemies will provide challenges for the player and enhance gameplay.

• Create Enemy Object:

  • Design an enemy object with basic properties like health and speed.

• Enemy Movement:

  • Implement simple AI for enemies to move back and forth.

  if (x <= left_bound || x >= right_bound) {
      hspeed = -hspeed; // Reverse direction
  }
  

• Collision with Player:

  • Decide on the enemy's behavior when it collides with the player (e.g., lose health).

  if (place_meeting(x, y, obj_player)) {
      obj_player.health -= enemy_damage;
  }
  

Step 3: Creating Checkpoints

Checkpoints will allow players to respawn at specific locations instead of starting over.

• Define Checkpoint Object:

  • Create a checkpoint object. When the player collides with it, save the player's position.

• Save Player Position:

  • In the checkpoint object's collision event with the player, set the player's saved position.

  obj_player.saved_position = {x: player.x, y: player.y};
  

• Respawn Logic:

  • In your player object, add logic to reset the player’s position to the saved position upon death.

  if (player_health <= 0) {
      x = saved_position.x;
      y = saved_position.y;
      player_health = max_health; // Reset health
  }
  

Step 4: Implementing Combat Mechanics

Combat mechanics will allow players to attack enemies.

• Add Attack Input:

  • Detect input for attacking (e.g., key press).

  if (keyboard_check_pressed(vk_space)) {
      attack();
  }
  

• Define the Attack Function:

  • Create an attack function that checks for enemy collisions and damages them.

  function attack() {
      var enemy = instance_place(x, y, obj_enemy);
      if (enemy) {
          enemy.health -= attack_damage;
      }
  }
  

• Enemy Health Management:

  • Remove the enemy when its health drops to zero.

  if (health <= 0) {
      instance_destroy();
  }
  

Conclusion

In this tutorial, you have learned how to implement wall jumps, enemies, checkpoints, and combat mechanics in your GameMaker platformer. These features will significantly enhance your game's interactivity and player engagement.

Next, consider refining your game by exploring additional features such as power-ups, level design, and advanced enemy behaviors. Happy developing!