Overview

Magnet Agent’s gameplay is a 2D puzzle game based on Physics and Magnetic interaction.

The player controls Magnet Boy who interacts with other magnets in the environment using his magnetic powers. For example, when he touches a magnet with the same polarity, he is repelled and bounces into the air; when he touches one with the opposite polarity, he is attracted toward it.

Players do not control the magnet man directly. Instead, they must strategically place magnets in the scene to guide him safely to the destination.

https://drive.google.com/file/d/1s0VR2wAQBo5k56xSiJCQIrIO9LBYQ8iS/view?usp=sharing

There are four modules included in the core gameplay system:

• Character
  • Includes movement, character state and magnetic effects.
  • Uses State design pattern to manage the character’s states and behaviours.
• Interaction
  • Interactive objects include flags, magnets and converts etc.
  • Provides interfaces for integration with other modules.
• Level Flow Management
  • Uses State design pattern to manage level status.

Character

• Utilizes FSM (Finite State Machine) to manage character states.

  • Developed this FSM package to handle all instances where finite state machines were required in the project.

  using Audio_Zenject;
  using FSM;
  using System.Collections.Generic;
  using UnityEngine;
  
  public class Character : MonoBehaviour{
  	private string currentStateName;
  	protected IStateMachine _stateMachine;
  	
  	protected bool isPlaying=false;
  	protected bool isPlanning = false;
  	protected bool isWinning=false;
  	protected bool instantDeath=false;
  	
  	protected virtual void InitializeStates()
  	{
  	    List<IState> states = new List<IState>();
  	    states.Add(InitState_Spawned());
  	    states.Add(InitState_InTheAir_Planning());
  	    states.Add(InitState_Idle());
  	    states.Add(InitState_Moving());
  	    states.Add(InitState_InTheAir());
  	    states.Add(InitState_Die());
  	    states.Add(InitState_UnderControl());
  	    states.Add(InitState_Attached());
  	    states.Add(InitState_Win());
  	
  	    var stateMachine= new StateMachine(states, key_spawned);
  	    _stateMachine = stateMachine;
  	    stateMachine.OnStateChanged.AddListener((state) =>
  	    {
  	        currentStateName = state.GetName();
  	    });
  	
  	    _stateMachine.Initialize();
  	
  	}
  }
  

• Manages the animator, movement, and magnetic interactions.

• Provides condition checks — e.g., whether the player is airborne, in contact with traps, or interacting with items.

protected bool CheckIsGrounded()
{
    if (_movement.IsGrounded())
    {
        return true;
    }
    return false;
}

private bool CheckTrap()
{
    return Physics2D.OverlapCircle(_center.position, 0.5f, _settings.trapLayer);
}

private bool CheckInteractable(out IInteractable obj)
{
    var hit = Physics2D.OverlapCircle(_center.position, 0.3f, _interactableLayer);

    if (hit)
    {
        obj = hit.GetComponent<IInteractable>();
        if (obj != null)
        {
            return true;
        }
    }
    obj = null;
    return false;
}

Interaction

• Interfaces
  • IItem provides an interface to link to ItemDatabase.
  • IInteractable defines the interactive behaviors of interactable objects.
  • IPolarizable is an interface that defines magnetic objects and exposes their polarity through an external accessor.
  • IMagnetic inherits from IPolarizable and specifies how magnetic objects interact with other IMagnetic entities.

Level Flow Management

GameController.cs

• Utilizes FSM (Finite State Machine) to manage level states:
  • Plan: The player can place or remove items on the map.
  • Play: The player can no longer edit the map, and characters begin to move.
  • Win Anim: The player achieves the level goal, triggering the win animation.
  • Win: After the win animation, the conclusion page appears.
• Uses UnityEvent<string> OnStateChanged to synchronize level states across characters, items, and UI elements.