Hey there! Let's break down your problem step by step— I know how frustrating it can be when tutorial code doesn't work as expected, especially when you're just starting out with grid-based movement like Pokémon in Unity.

First: Fix Your Broken Code #

Looking at your script, there are two critical issues that are making it fail completely:

1. All directions are set to Vector3.up: You're using the same direction for W/A/S/D—so no matter which key you press, the player only moves up.
2. Typo in coroutine call: You wrote StartCoroutine/(...) instead of StartCoroutine(...) (slash instead of parentheses).

Here's the corrected base version of your code, with proper direction mapping:

using System.Collections;
using UnityEngine;

public class GridMovement : MonoBehaviour {
    private bool isMoving;
    private Vector3 origPos, targetPos;
    private float timeToMove = 0.2f;
    // Define your grid cell size (usually 1 unit for top-down Pokémon style)
    public float gridCellSize = 1f;

    void Update() {
        if (isMoving) return; // Skip input if already moving

        if (Input.GetKeyDown(KeyCode.W)) StartCoroutine(MovePlayer(Vector3.forward * gridCellSize));
        if (Input.GetKeyDown(KeyCode.A)) StartCoroutine(MovePlayer(Vector3.left * gridCellSize));
        if (Input.GetKeyDown(KeyCode.S)) StartCoroutine(MovePlayer(Vector3.back * gridCellSize));
        if (Input.GetKeyDown(KeyCode.D)) StartCoroutine(MovePlayer(Vector3.right * gridCellSize));
    }

    private IEnumerator MovePlayer(Vector3 direction) {
        isMoving = true;
        float elapsedTime = 0;
        origPos = transform.position;
        targetPos = origPos + direction;

        while (elapsedTime < timeToMove) {
            transform.position = Vector3.Lerp(origPos, targetPos, elapsedTime / timeToMove);
            elapsedTime += Time.deltaTime;
            yield return null;
        }
        transform.position = targetPos;
        isMoving = false;
    }
}

Note: I switched GetKey to GetKeyDown so the player moves once per key press, not continuously—this is more true to Pokémon's movement style.

Adding Collision Detection #

To stop the player from moving through walls/obstacles, we need to check if the target position is clear before starting the movement. Here's how to add that:

1. Set up layers: Create an "Obstacles" layer in Unity and assign all your wall/block objects to it.
2. Add collision check logic: Modify the script to validate the target position before moving.

Updated code with collision detection:

using System.Collections;
using UnityEngine;

public class GridMovement : MonoBehaviour {
    private bool isMoving;
    private Vector3 origPos, targetPos;
    private float timeToMove = 0.2f;
    public float gridCellSize = 1f;
    // Assign your Obstacles layer here in the Inspector
    public LayerMask obstacleLayer;

    void Update() {
        if (isMoving) return;

        if (Input.GetKeyDown(KeyCode.W)) AttemptMove(Vector3.forward * gridCellSize);
        if (Input.GetKeyDown(KeyCode.A)) AttemptMove(Vector3.left * gridCellSize);
        if (Input.GetKeyDown(KeyCode.S)) AttemptMove(Vector3.back * gridCellSize);
        if (Input.GetKeyDown(KeyCode.D)) AttemptMove(Vector3.right * gridCellSize);
    }

    private void AttemptMove(Vector3 direction) {
        targetPos = transform.position + direction;
        // Check if target position is free of obstacles
        if (IsPositionClear(targetPos)) {
            StartCoroutine(MovePlayer(direction));
        }
    }

    private bool IsPositionClear(Vector3 position) {
        // Use OverlapBox to check for collisions at the target position
        // Adjust the box size to match your player's collider
        Collider[] hitColliders = Physics.OverlapBox(position, transform.localScale / 2, Quaternion.identity, obstacleLayer);
        return hitColliders.Length == 0;
    }

    private IEnumerator MovePlayer(Vector3 direction) {
        isMoving = true;
        float elapsedTime = 0;
        origPos = transform.position;
        targetPos = origPos + direction;

        while (elapsedTime < timeToMove) {
            transform.position = Vector3.Lerp(origPos, targetPos, elapsedTime / timeToMove);
            elapsedTime += Time.deltaTime;
            yield return null;
        }
        transform.position = targetPos;
        isMoving = false;
    }
}

Make sure your player has a collider (like a BoxCollider) and that obstacle objects have colliders set to "Is Trigger" disabled.

Reliable Learning Resources for Pokémon-Style Games #

Since you mentioned struggling with unhelpful tutorials, here are some trustworthy places to learn (all within Unity's ecosystem or well-respected developer communities):

• Unity Learn Official Tutorials: The official Unity Learn platform has a dedicated 2D RPG series that covers grid movement, collision, and other core systems similar to Pokémon. Look for courses tagged "Grid-Based Movement" or "2D RPG".
• Unity Forums: The official Unity Forums have a dedicated "Game Development" section where you can ask specific questions, and many experienced developers share step-by-step guides for grid movement systems.
• Unity Asset Store Sample Projects: Some free sample projects on the Asset Store focus on top-down grid-based games—downloading these lets you dissect working code and see how professionals implement movement and collision.
• Curated YouTube Creator Series: Look for creators who specialize in Unity 2D tutorials and have a track record of clear, tested code (avoid one-off videos with untested scripts). Many creators break down Pokémon-style systems piece by piece, from movement to battle mechanics.

Final Tips for Beginners #

• Start small: Don't try to build the entire Pokémon game at once. Focus on getting movement working first, then add collision, then NPC interactions, etc.
• Use debug tools: Unity's Debug.DrawRay or Debug.DrawCube can help you visualize your collision checks and make sure your target positions are correct.
• Read Unity's official documentation: The docs for Physics.OverlapBox, Coroutines, and Vector3 are your best friends—they explain exactly how each function works and give examples.

内容的提问来源于stack exchange，提问作者cireon