16 Where to from here?

This chapter looks beyond the tutorial shoot-’em‑up to show how to turn a simple prototype into a fuller NES project, how to push the console with cartridge‑based enhancements, and how to share a finished game with players. It opens with practical ways to deepen polish and replay value, explains how mappers unlock more memory, graphics, audio, and timing tricks, and then outlines the spectrum of release options—from free demos and paid ROMs to boxed cartridges—before closing with inspiration from other NES‑friendly genres.

For the sample game, suggested upgrades include adding enemy variety and behaviors (new attack patterns and reactions), awarding extra lives at score milestones, and ramping difficulty with faster movement or staged waves. Audio gets special attention: choose music that fits screens and levels, and add distinct cues like an extra‑life jingle. “Arcade touches” round out the presentation—high‑score storage (even battery‑backed), animated title screens, and an attract‑mode gameplay demo. The chapter then explores how cartridges extend the NES through bank‑switching mappers: gaining more PRG/CHR space, optional four‑screen nametables, per‑tile attribute enhancements, and scanline interrupts for effects like split‑screen scrolling. It also surveys expanded sound via mapper chips (additional pulse, wavetable, PCM, and FM channels) and covers save support through battery‑backed RAM or, more rarely, EEPROM.

On publishing, the chapter balances audience reach and effort: offer free or limited ROMs to build interest, sell downloadable ROMs despite inevitable sharing, or aim for physical carts for the quintessential retro experience. Self‑publishing requires choosing a compatible PCB/mapper, sourcing shells, budgeting for manuals and boxes, and possibly using crowdfunding to size a print run; working with a publisher trades control for reduced risk and turnkey production, with contracts advised. Finally, it spotlights genres that shine on NES—single‑screen and scrolling platformers that exploit mirroring and scrolling, action‑adventures in the mold of The Legend of Zelda, and RPGs influenced by series like Ultima—encouraging developers to leverage hardware extensions to build larger, more varied games.

Standard NES Cartridge Memory Layout

Example Expanded NES Cartridge Memory Layout

Adding an extra 2k of name table ram allows four separate tables.

UNROM Printed Circuit Board (PCB) from Muramasa

Donkey Kong on the NES

Megaman on the NES

Super Marios Bros on the NES

Handling a horizontally scrolling area.

The Legend of Zelda on the NES

Ultima Exodus on the NES

• There are quite a few things that can be added to our sample game to make it more polished and compelling for players, such as a high score table, extra difficulty, music, and more arcade touches.
• The NES was popular and along with its capability to be extended via extra hardware in the game cartridges, it championed several more complex game genres, like platformers, action-adventure games as well as role playing games.
• Modern titles for the NES can be published several ways, either via a free ROM download of a demo or even full version to allow as many people access to your game as possible, or via sale of a ROM online, and maybe even a produced in physical cartridge form with a proper box and manual to be enjoyed by the any NES enthusiasts and collectors.
• NES cartridges are not limited to 32k of PRG ROM and 8k of CHR ROM, using custom logic chips more space for code and patterns can be used, allowing much more complex and larger games.
• Not only can cartridges contain more storage they can also provide additional sound channels, to allow richer music and more sound effects to be played without interrupting other sounds already being played.
• Cartridges can also provide space for progress in games to be saved either using an inbuilt battery or EEPROM memory.
• There are well over 100 documented Mappers that add different capabilities to the NES console, one of the main reasons the console enjoyed such a long life.

FAQ