Arcade Game Designer, or AGD, is a game-making program for the ZX Spectrum that Jonathan Cauldwell first released in 2008, more than a quarter of a century after the Spectrum’s launch. It does for arcade games what The Quill did for text adventures in 1983: an author who has never written a line of Z80 assembly draws the sprites and scenery, lays out the screens, writes short scripts for what each thing should do, and gets a finished machine-code game that runs on a real Spectrum. Cauldwell gives it away, and asks nothing from the games made with it.
Fast facts
- Author: Jonathan Cauldwell.
- First released: 2008, for the 48K and 128K Spectrum.
- Major versions: 3.0 in 2012, whose editor needs a 128K machine; 4.0 in 2013; 4.8, the latest, in February 2019.
- Other versions: an Amstrad CPC edition, a ROM edition that boots straight into AGD and frees the whole of the Spectrum’s RAM, and the Windows-based Multi-Platform Arcade Game Designer.
- Price: free, with no royalties on games made with it.
How it works
AGD runs on the Spectrum itself, which today usually means in an emulator. An author builds a game from three kinds of material: blocks, the pieces of scenery; sprites, the moving characters; and screens, which arrange the blocks into rooms. What everything does is written as short programs in a simplified language instead of assembly, and templates come with the tool to start from. AGD turns the result into a standalone Spectrum game.
Spectrum Computing notes that games created with one version of AGD are not compatible with the others.
The games
Retro Gamer was already following AGD games in 2012. Reporting the release of version 3, it noted that earlier versions had been behind “the Bog Brothers’ excellent Trooper Point 5” as well as Paul Jenkinson’s Space Disposal and Chopper Drop. By 2017 the free Spectrum magazine ZX Spectrum Gamer called it “the superb Arcade Game Designer by Jonathan Cauldwell” and wrote that it “has been the basis for the majority of recent Spectrum homebrew titles, such as Zombo by Malcolm Kirk”. The same magazine’s cover game the following year, Paul Weller’s Aeon, was credited as “made mostly in Jonathan Cauldwell’s Arcade Game Designer”.
Cauldwell’s own page puts the total at more than 200 games. The Spectrum Computing database, which lists games by the tool that made them, credits AGD with more than 400 titles released between 2010 and 2025.
ZX Spectrum Gamer’s writer, who admitted he “could never get my head around machine code”, saw AGD and PAW as the two programs that mattered most for the Spectrum’s future: tools “allowing average Joes like you and me to create essential content that will keep the machine and its community alive”.
Beyond the Spectrum
Cauldwell’s later tool, the Multi-Platform Arcade Game Designer (MPAGD), runs on Windows instead of the Spectrum. It imports games made with AGD 4.0 or later and builds them for the Spectrum, MSX, Amstrad CPC, BBC Micro Model B, Dragon 32 and 64, Acorn Atom, Enterprise and VZ200. Cauldwell describes it as “far more powerful than the original AGD”, and it is free on the same terms: “It is not my intention that anyone should ever pay royalties or subscriptions for a game developed with any of my game designers.”
In 2017 ZX Spectrum Gamer reported that a version for the ZX Spectrum Next was in development. In August 2026 Next Magazine, surveying the game-making engines being built for the Next, still described AGD as a tool “for the original Spectrum”, one that “has been used to create some truly brilliant games on the platform” and is “even used by kids in primary schools”.
Released source code
The MPAGD download includes the source code of its compiler and game engines, so that other programmers can adapt it to more machines. Cauldwell’s download page does not state a licence.
Sources
- Retro Gamer issue 105, 2012: homebrew news on the release of AGD version 3 (128K needed for the editor; Trooper Point 5, Space Disposal, Chopper Drop).
- Retro Gamer issue 118, 2013: homebrew section, “Arcade Game Designer 4.0”.
- ZX Spectrum Gamer issue 4, May 2017: “What Dreams May Come” (AGD as “the glue behind many a recent Spectrum homebrew title”, Zombo, a Next version in development, the “average Joes” quotation).
- ZX Spectrum Gamer issue 5, April 2018: cover game Aeon (Sunteam), credited as “made mostly in Jonathan Cauldwell’s Arcade Game Designer”.
- Next Magazine issue 15, August 2026, p. 14: AGD “for the original Spectrum” and in primary schools.
- Jonathan Cauldwell, “Arcade Game Designer”, itch.io download page (web, secondary): versions 2.7 and 4.8 (February 2019), AGDCPC and ROM AGD, 48K and 128K, free with no royalties, more than 200 games. https://jonathan-cauldwell.itch.io/arcade-game-designer
- Jonathan Cauldwell, “Multi-Platform Arcade Game Designer”, itch.io download page (web, secondary): target machines, the royalties quotation, import from AGD 4.0, and compiler and engine source in the download. https://jonathan-cauldwell.itch.io/multi-platform-arcade-game-designer
- Spectrum Computing, “Arcade Game Designer” (database, secondary): 2008 release, version history, incompatibility between versions, games made with AGD. https://spectrumcomputing.co.uk/entry/20176/ZX-Spectrum/Arcade_Game_Designer