Retrobator is a modern NES emulator, available on Itch.io and (soon) Steam.

Features

The Bonkers Edition adds:

Timeline

The Timeline records every frame of gameplay history. Go back and watch a replay, or branch reality by playing a different future.

Timeline screenshot

View Demo

Use mouse, keyboard, or gamepad triggers to navigate.

Note: Stores a maximum of 1 hour per game by default (configurable), using around 150 MB of disk space per hour.

AutoMap

The AutoMap stitches together game maps while you wander. Zoom out, pan around, admire your cartographic genius.

AutoMap example

View Demo

Zoom: mouse wheel or right gamepad stick.
Pan: right-click+drag or left gamepad stick.

Note: Warp-heavy games or parallax scrolling can confuse the map-bot. If the maps look like modern art, let us know in Issues, or toggle AutoMap off.

Sprite Replay

When zoomed out, watch recent gameplay animating looping on top of the AutoMap.

Sprite Replay is configurable in the Sprite Effects menu.

Trail Effects

Adds an afterimage effect behind sprites, creating visually appealing trails.

Sam's Journey Trail Effect Off
→
Sam's Journey Trail Effect On

View Demo

Configure this effect from the Sprite Effects menu.

Motion Interpolation

Retrobator tracks and blends tile movement between frames for smoother scrolling. It really shines in slow-motion or with a >60hz monitor.

Motion interpolation off
→
Motion interpolation on

View Demo

To slow things down, lightly depress the gamepad triggers or hold the slow-motion key.

AI Assistant

Note: Experimental and OpenAI-metered. More providers are in the works.

Enable a generative AI agent. Issue voice or text commands, ask questions, or let it react to in-game events.

Customize the assistant personality and voice by assigning a different actor:

AI Assistant interface

View Demo

To communicate, use the Tab key (or left shoulder gamepad button) for push-to-talk, or open the chat window (grave accent `) to type.

Example commands:

Note: The assistant will see a screenshot of the game (as permitted) during each exchange. To provide richer context, feed it events.

OpenAI Setup

To enable the AI Assistant, you must configure the OpenAI AI provider:

  1. Join platform.openai.com.
  2. Under (Settings) → Billing, add some “Pay as you go” credit ($5 is plenty to start with).
  3. In (Settings) → API Keys make a secret key and copy it.
  4. Back in Retrobator, open the Providers menu, paste the key into the Key field, done.

Minimizing API Costs

In the Providers menu:

In the Assistant menu:

Track your spend at platform.openai.com/usage.

ElevenLabs Voices

Optionally, you may configure the ElevenLabs provider to unlock a larger and more diverse set of voices to choose from. ElevenLabs offers a Free tier, with some special voices restricted to the Starter tier.

ElevenLabs also provides sound effect generation, useful for scripting.

ElevenLabs Setup

To enable:

Scripting

Note: Scripts are an experimental preview feature; it will likely change as we iron out the kinks.

In the Scripting menu, you can create scripts that play sound effects or other sequences, triggered by events or button presses.

Scripting Menu

View Demo

Some of the built-in scripts:

  - Play crowd cheering when finishing the game, booing when game over, etc.
  - When idle, play a musical montage of your previous exploits.
  - (AI) Play an instant replay w/ AI reaction when you die.
  - (AI) Generate and voice an investigative report on Game Over.
  - (AI) Generate and voice a movie trailer on demand.
  - (AI) Hotkey to invoke an AI translator for on-screen text.
 (and more)

Import your own sounds/music/images or generate them using the ElevenLabs provider. Pre-generated sound effects are also included with Retrobator.

Note: Some scripts use actors assigned to ElevenLabs voices. For the best experience, see here for enabling specific ElevenLabs voices.

Events

Mark simple moments (deaths, game-overs, etc.) and train Retrobator to track them on the Timeline and feed them to the AI Assistant.

Retrobator ships with built-in events for many popular games.

View Games Note: The built-in events are tied to a specific version of each game. Games listed are the U.S./World versions;
Game
Bad Dudes
Blaster Master
Castlevania
Contra
Double Dragon
Dragon Warrior
Duck Hunt
Ducktales
Excitebike
Faxanadu
Final Fantasy
Flea!2
Ironsword
Kid Icarus
Legend of Zelda, The
Marble Madness
Mega Man 2
Mega Man 3
Metroid
Mike Tyson's Punch-Out!
Ninja Gaiden
Ninja Gaiden 2
Pinball
Pinky
Pinky Xmas
Pinky Xmas
Rad Racer
Startropics
Super Mario Bros
Super Mario Bros 2
Super Mario Bros 3
Tecmo Bowl
TMNT
Tetris
T&C Surf Designs
Vegas Dream
Zanac
Zelda 2

Events are mainly used to enable AI shenanigans; expect more event-driven features soon!

Training an Event

Give Retrobator real examples, let it train, then test and fine-tune.

View Instructions

Events Menu

  1. Play the game until you have at least two occurrences of the event in your Timeline. The more, the better.
  2. In the Events window, hit the "+" button to create a new event.
  3. For each occurrence in the timeline, go to the frame where it happened. It need not be exact, but the closer, the better.
    4. Next to Training Set, hit the "+" button to add the frame as a training instance.
  4. Smash Train. If it fails:
    1. Double-check that all instances are added.
    2. (If needed) Adjust the training range to include/exclude occurrences in the timeline.
  5. Test the event by playing the game.
    - If an occurrence goes undetected, add the frame to the training set, and train again.
    - When a false positive is detected, select the occurrence and hit the False Positive button to remove it and update the training data.

Trained events can be exported as packages and shared.

Backdrops

Note: This feature has been voted off the island, as it required too much manual effort. Backdrops may return in a future season of the show.

Packages

Import/export your hard-won settings to share with the world.

Currently supported exports:

Packages wear the .b8r extension. Handle them in the Packages menu.

Support

Bug? Idea? Hit Issues or join the chatter in Discussions.

Q&A

Supported platforms?

Windows 10+ (x64) today; more OSes on the wish list.

Supported hardware?

A modern PC with a discrete GPU is ideal, although Retrobator may run on humbler rigs.

Which games work?

Any digital NES/Famicom title in .nes format (most of them). For the outliers, let us know here.

Where do I find games?

Retrobator does not include ROMs. Browse indie NES gems on Itch.io, or back up your own carts with INLRetro/RetroBlaster.

Steam release—when?

Steam’s external-service rules would inflate your AI bill. We’re waiting until we can bundle an offline model inside Retrobator.

Lore?

Retrobator is forged from caffeine, shower epiphanies, duct tape, and a respectable mid-life crisis.

Who’s “we”?

Currently: one wildly motivated human.

What’s next?

More goodies are in the pipe. Drop requests in Discussions.

Credits

Demonstrated games:

Pinky Xmas - Axbakk Games
Pinky - Axbakk Games
Sam's Journey - Knights of Bytes
Flea!2 - Lowtek Games
neMULEsis - John Vanderhoef
Blade Buster - HLC Project
Old Towers - RetroSouls
Super Bat Puncher (Demo) - Morphcat Games
Cube - ResidentEmil

Notices

Retrobator is not affiliated with or endorsed by Nintendo.