How AI-Powered Cursor Can Slash Game Development Time: A Real MMO Case Study

Introduction: Accelerating Game Development with AI

This article presents a hands‑on case from a large‑scale multiplayer online card game, demonstrating how to use the Cursor AI agent to speed up development. It focuses on concrete steps, prompt engineering, and practical methods that let AI assist across the entire development pipeline.

Project Overview

The project is a top‑grossing MMO card game with monthly revenue exceeding one hundred million yuan and more than 4,000 source files.

Software Environment

Object: cursor, Version: 0.48.x, Cost: $32 per month, Note: enterprise version required

Large language model: claude‑3.7 sonnect‑thinking, Cost: about $80 per month, Note: other thinking‑enabled models are also usable

Programming language: erlang R25, Cost: free, Note: focus on development approach rather than language specifics

Requirement Summary – Guild Mining

1. Guild members can consume their "shovel" item to dig the guild mine;
2. Each shovel consumption increases mine depth by 1 meter;
3. When the mine reaches depths such as 50 m or 100 m, all guild members receive rewards;
4. Players also receive rewards based on the number of digs;
5. Guild leaderboard compares mine depths between guilds;
6. Internal leaderboard compares individual dig counts;
7. Additional detailed requirements are omitted.

Only a simplified, de‑identified version of the requirements is shown; the illustration was generated by Doubao.

Task Decomposition

Understand requirements (currently Cursor cannot read Excel plans directly, so manual interpretation is needed).

Create a requirement description file named guild_mining.md.

Design data structures (add to guild_mining.hrl).

Design configuration format (e.g., config_guild_mining.json).

Iteratively develop each feature point, starting with the mining operation.

%% guild_mining.hrl
%% Manager data structure
-record(guild_mining, {
    guild_id = 0,          % guild id
    depth = 0,            % mining depth
    rewards = #{},        % rewards achieved per depth {RewardId => Time}
    extra = #{}           % additional data
}).

%% Player data structure
-record(role_guild_mining, {
    role_id = 0,          % player id
    dig_times = 0,        % number of digs
    rewards = [],         % list of personal reward IDs already claimed
    guild_rewards = [],   % list of guild reward IDs already claimed
    extra = #{}           % additional data
}).

{
  "id": 1,
  "name": "Guild Mining",
  "item_id": 1001,
  "per_dig_depth": 1,
  "guild_rank_id": 1,
  "personal_rank_id": 2,
  "guild_rewards": [
    {"reward_id": 1, "depth": 50, "reward": {"item_id": 10001, "item_num": 1}},
    {"reward_id": 2, "depth": 100, "reward": {"item_id": 10002, "item_num": 1}}
  ],
  "personal_rewards": [
    {"reward_id": 1, "times": 10, "reward": {"item_id": 10003, "item_num": 1}},
    {"reward_id": 2, "times": 20, "reward": {"item_id": 10004, "item_num": 1}}
  ]
}

Feature Point – Mining Operation

# 4.1 Mining Operation
Rules:
 a. Only guild members may mine.
 b. Consumes the item defined by config_guild_mining.item_id.
    Increase mine depth = item count * config_guild_mining.per_dig_depth.
 c. Increments the player's personal dig count.

Prompt Templates for Cursor

// Implementation idea prompt
1. Read @guild_mining.md
2. Understand 4.1
3. List your implementation plan using a format like 1.1

// Coding prompt
1. Implement feature 4.1 according to your plan.
2. Provide complete documentation and specs.

Code Review Checklist (Optional)

1. Verify each called function's parameter count, types, and return values.
2. Check that all input parameters are validated (type, range, format).
3. Ensure boundary conditions (null, extreme values) are handled.
4. Validate error‑handling flow consistency.
5. Confirm all branches are covered and no dead code exists.
6. Compare spec‑defined data structures with actual code usage.
7. Ensure constant values are consistent across the codebase.
8. Verify function implementation matches its documentation.

Unit Test Prompt (Optional)

Generate unit tests for lib_role_guild_mining:dig_mine/2 covering:
1. Mock dependencies with mech.
2. All branch paths.
3. Boundary conditions.
4. Exception scenarios.

Key Takeaways

Assign high‑value tasks (design, review) to humans and repetitive coding/testing to Cursor.

Drive development with .md‑driven specifications to keep context continuous.

Break complex features into small, manageable tasks for better quality control.

Maintain human oversight; AI acts as an accelerator, not a replacement.

Future Directions

Integrate Retrieval‑Augmented Generation so Cursor can directly read design documents.

Automate post‑commit workflows: code review, test generation, and execution.

Connect Cursor with project‑management tools (Redmine, Jira) to ingest bug reports and attempt automated fixes.