A free and open source, web-based online rhythm action game.

Started in 2015, it is built based on modern HTML5 technology and libraries such as React and Pixi.js.

Play the game

# Etymology

The original name of the game was “beat☆music☆sequence”. This name was derived from the file format that it uses, .bms (Be-Music Source) (opens new window). Later, I shortened the name to Bemuse, which happens to be a valid English word, meaning “to make confused”.

# Origin

I built this game as a playground in applying software engineering principles and practices. It is also my graduation project (opens new window). The project is open source, and has automated tests as well as a CI/CD pipeline around it.

Source code on GitHub

# Features

The gameplay is heavily inspired and influenced by Lunatic Rave 2, beatmaniaIIDX, and O2Jam. It is key sounded, meaning that each individual note gets its own sound. The song will sound off if you did not hit the notes correctly.

I created this project because most PC rhythm games only work on Windows, and I use a Mac. I originally designed this project for desktops and iPads, but being web based, the game could be made to work on more devices as mobile devices become more powerful over time, bringing a truly cross platform experience.

In 2018, a 3D mode is added, and the game can be enjoyed in mobile phones.

Party mode lets multiple people play Bemuse together.

As of 2019, Bemuse has over 15,000 monthly active players.

# Development

# Software engineering

The first few weeks of development consists solely of setting up the project: webpack with loaders for Jade (opens new window), SCSS (opens new window), and 6to5 (opens new window) (now Babel (opens new window)). webpack-dev-server (opens new window), JSHint (opens new window), JSCS (opens new window), Jasmine (opens new window), Istanbul (opens new window), Code Climate (opens new window), Travis CI (opens new window), among others.

Developing software in an Agile way entails taking to heart that “Working software is the primary measure of progress.” Within a month, I deployed a teaser page (opens new window) with a technical demo, which proves that a rhythm game can indeed be built with current browser technology.

Software engineering for me is about striking a healthy balance between building the right thing and building it right. Although I want to ship things fast, I want to do it on top of a sound foundation.

Here are some technical choices that I felt very happy about when I look back:

# Experiment with confidence and explore with safety

Clean architecture and tests enable me to experiment with new things. It lets me make many two-way door decisions (opens new window). I can try out new (and perhaps not-so-mainstream) libraries and tools (such as webpack (at the time), Ramda, Ractive, and Bacon.js).

If they worked out well, then I could keep them (webpack being one example). Otherwise, if situation calls, I could switch to more boring (opens new window), stable, tried-and-true solutions (such as Lodash, React, and Redux) at a relatively low cost.

It allowed me to update the project to use new tools and follow the general direction of JavaScript community:

Having a system for automated tests in place also allowed me to implement support for new file format in a single night (opens new window).

# Music

Bemuse plays song files in Be-Music Source (opens new window) .bms file format. It is the same format used in Lunatic Rave 2 and others, and has a thriving community around it where ‘BMS artists’ collectively publish hundreds of original songs every year (opens new window).

Most playable songs in the game, I reached out to BMS artists and asked for permission to use them in the game. Most artists are happy to allow me to use their songs for free, given that Bemuse is also a free game.

The background music for the game screens, as well as some playable songs, I composed myself.

published by at , last updated at