Is Game Boy Advance Development still Relevant?
Game Boy Advance development offers a rare look at low-level 2D rendering, manual memory management, and hardware constraints. See how it connects to modern engines and why it’s still a valuable learning experience.
Modern game development has made incredible leaps in accessibility. Engines like Unity, Godot, and Unreal allow developers to create visually rich experiences without ever worrying about the underlying hardware. Rendering pipelines, sprite batching, and memory management are abstracted away, leaving developers free to focus on gameplay and design. While this abstraction is a net positive, it also means that few developers truly understand how rendering can work at a hardware level.
The Game Boy Advance (GBA) offers a unique opportunity to bridge that gap, at least for 2D games. Unlike modern engines that push pixels through a software pipeline, the GBA has a hardware-accelerated tile and sprite system that developers must work within. Understanding this system provides valuable insight into how classic consoles optimized performance, and by extension, how modern tile-based rendering engines work under the hood. While there is little direct practical application to GBA development today, except for hobbyist retro enthusiasts, it remains a valuable learning opportunity—one that challenges developers to think differently about rendering, memory management, and compiling binaries for an entirely different platform.
This article draws from experience developing FireInTheSky, a top-down Game Boy Advance demo showcasing the console’s tile and sprite rendering capabilities. The artwork used in the demo was created by Ari Feldman and is part of his SpriteLib library, a collection of freely available sprite assets for game development.
The GBA Graphics Pipeline
The Game Boy Advance (GBA) is a 2D-first console, designed around hardware-accelerated tilemaps and sprites rather than modern pixel-based rendering. Unlike on a PC, where developers manipulate an image buffer directly, the GBA’s graphics pipeline is built around dedicated memory regions for backgrounds, sprites, and palettes. This forces developers to think in terms of tiles and objects, a concept that still exists in modern engines but is rarely encountered at the hardware level. Instead of redrawing entire frames, developers construct environments using preloaded tiles, optimizing memory usage and performance.
The tile and sprite engine comes with important constraints. Backgrounds are made up of tilemaps, where each tile is 8×8 pixels and stored in character blocks, specific VRAM segments for tile data. The GBA supports up to four background layers, each capable of scrolling independently, making them useful for effects like parallax scrolling. Some modes even allow transformations such as rotation and scaling. Sprites, also known as objects, are managed through object attribute memory (OAM), which tracks up to 128 individual sprites. Each sprite is limited in size and must be selected from a 16×16 tile grid stored in object character memory (OBJ VRAM). While these limitations can seem restrictive, they are what make the GBA an efficient platform, pushing developers to work within constraints similar to those of the SNES and arcade hardware.
Adding another layer of efficiency, the GBA uses a palette-based color system rather than storing full 16-bit color values for every pixel. There are two primary palettes: one for background tiles and one for sprites, each capable of holding 256 colors, with each color represented as a 15-bit RGB value. Instead of storing unique color data for every tile or sprite, developers use index-based colors, referencing palette entries instead of raw RGB values. This drastically reduces memory usage while still allowing for rich, colorful visuals.
The palette system also enables dynamic color swapping, a technique commonly used for palette cycling effects, day/night transitions, and enemy recoloring without needing additional sprite memory. By simply adjusting the color values in the palette, entire sections of a scene can be recolored without touching the actual sprite or tile data. This hardware feature was essential for many GBA games, allowing developers to reuse assets in creative ways while working within the system’s 96 KB of VRAM constraints.
The GBA as a Development Platform
Unlike programming for a PC, GBA development requires compiling code for a completely different architecture. The system runs on an ARM7TDMI processor, a 32-bit RISC CPU clocked at 16.78 MHz. In contrast, modern devices like the iPhone 16 are powered by Apple's A18 chip, which features a six-core CPU with two performance cores running at 4.04 GHz and four efficiency cores at 2.2 GHz. This means that the GBA's processor operates at a frequency approximately 240 times slower than the high-performance cores of the A18 chip. Additionally, the A18 chip incorporates advanced features such as multiple cores and a 16-core Neural Engine, capabilities that were unimaginable at the time of the GBA's release. While today's processors handle complex tasks like 3D rendering and artificial intelligence computations, the ARM7TDMI was optimized for simple 2D games, requiring developers to work within its constraints through careful memory management and efficient code execution.
Because of its unique hardware, GBA development requires cross-compilation—a process where code is compiled on a PC but targeted for an entirely different platform. Unlike modern game development, where developers typically work with engines that abstract hardware differences, GBA programming requires thinking about CPU architecture and memory layout from the start. While this level of control is unnecessary for most modern applications, it remains relevant in embedded systems, retro console development, and even custom hardware projects. Understanding how code interacts with a specific processor, rather than relying on an engine’s generalized runtime, provides a deeper appreciation for platform-specific optimization techniques.
Rodrigo Copetti
The GBA also lacks an operating system, meaning there are no system calls, memory managers, or high-level APIs to handle rendering, sound, or input. Instead, developers write directly to hardware registers mapped to specific memory locations, controlling every aspect of the system manually. While this might sound tedious compared to the event-driven programming found in modern engines, it offers complete control over performance and behavior. Many of the fundamental techniques used in GBA development—such as writing to memory-mapped I/O, managing game loops efficiently, and using hardware interrupts—are still relevant when working with embedded systems, low-level graphics programming, and even older consoles like the SNES.
Getting Started
Game Boy Advance development is not for the faint of heart. Unlike modern game engines that provide high-level scripting and automatic memory management, GBA development requires working directly in C or C++, with manual memory management and a low-level understanding of the hardware. Debugging tools are limited, meaning issues often require manually inspecting memory or adding on-screen debug output. Additionally, assets such as sprites, tilemaps, and palettes must be carefully formatted to fit within the GBA’s constraints, requiring additional conversion steps before they can be used. Everything about the development process is more hands-on than what most modern game developers are used to.
One of the most important decisions when starting out is choosing the right toolkit. For those looking to understand how the GBA works at a hardware level, the best choice is libTonc, a lightweight library that provides minimal abstractions while exposing the full capabilities of the system. However, developers more interested in creating a full retro-style game rather than working directly with hardware may prefer a higher-level framework like Butano, which simplifies development by handling things like rendering and asset management while still running on real GBA hardware. Unless you have a specific goal of learning GBA hardware at a low level, Butano is the better choice for most developers, as it simplifies development while still running on real GBA hardware.
gbadev-orgGValienteOnce a GBA program is compiled, it must be tested in an emulator or on real hardware. Emulators like mGBA and VisualBoyAdvance provide an essential development environment, allowing for rapid iteration and debugging. However, there’s nothing quite like seeing your code run on an actual Game Boy Advance. To do this, developers need a flash cart, a special cartridge that allows loading and running homebrew software on real hardware. Flash carts contain rewritable storage and a USB or SD card interface, enabling developers to test their games on an actual GBA. It’s important to note that just because something runs in an emulator doesn’t mean it will behave identically on hardware—timing differences, memory access quirks, and graphical rendering issues can all arise when switching between the two. Additionally, debugging on real hardware is extremely limited, making emulators the primary tool for development.
Why This Still Matters Today
Game Boy Advance development is a challenge unlike modern game programming. It requires an understanding of low-level graphics, manual memory management, and direct hardware manipulation—skills that most developers never encounter when working with engines like Unity, Godot, or GameMaker. Yet, the principles behind GBA development still exist today, even if they are hidden behind layers of abstraction.
Tile-based rendering, for example, remains a core concept in 2D game engines. Tools like Unity’s Tilemap system or Godot’s tile layers provide the same performance benefits that the GBA’s hardware-accelerated backgrounds were designed for, though modern engines handle the memory management behind the scenes. Sprite batching, another common optimization in modern engines, mirrors how the GBA processes sprites efficiently through OAM. Even the limitations of GBA development—such as working within strict memory constraints—parallel the challenges of optimizing for mobile games or low-powered embedded devices.
Developing for the GBA is not a practical skill in today’s industry, but it is a valuable learning experience. It forces developers to think critically about performance, memory, and rendering efficiency in a way that modern tools often obscure. For those interested in understanding how 2D games work at a deeper level, exploring GBA development can provide a unique perspective that carries over into modern game development, even if it’s just a hobbyist experiment.
