Notcher

Your notch. Your arcade.
Drag a NES or Game Boy ROM onto the MacBook notch and it plays right there. Or hover the notch for 20 built-in mini games. Esc takes you back to work.

⬇ Download Notcher for Mac · macOS 14 or later

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Notcher turns the notch into a small arcade that behaves like the Dynamic Island. It's built for the half-minute gaps in a workday: waiting on an AI agent, a build, a download or a compile.

Hover → Click → Play → Esc → Back to work.

Play your own ROMs

• Drag to play. Drag a .nes, .gb or .gbc file, or a .zip with one inside, toward the notch. It opens into a drop target; let go and the game starts. You can also click Add ROM in the Library, use Open ROM… (⌘O) in the menu bar, or choose Open With → Notcher in Finder.
• A library that remembers. Every game you add is kept on the Library page, with the last frame you saw as its poster. For You offers a Continue card for the game you played last. Right-click a game to start over, show it in Finder or remove it.
• Esc saves your spot. Leaving a game snapshots it, and the next launch continues exactly there. Battery saves (the cartridge's own save RAM) are written to disk every few seconds while you play. ⌘S / ⌘L give you a quick-save slot on top.
• Feels like a handheld. The picture sits in a bezel between a D-pad and A/B buttons that light up as you press them. NES games get soft scanlines, Game Boy games an LCD pixel grid (or switch to sharp pixels in Settings), and original Game Boy games come in classic green or Pocket grey.
• Keyboard or controller. Arrows or WASD move, X is A, Z is B, ↵ is Start, ⌫ is Select, hold tab to fast-forward and P pauses. Xbox, PlayStation, Switch Pro and MFi controllers work too.
• Emulators written for Notcher. Both consoles are emulated in plain Swift: a cycle-accurate 6502 with the NES picture and sound chips, and an SM83 with the Game Boy and Game Boy Color hardware. Emulation runs on its own thread and locks to your display's refresh, and the audio stream adjusts its rate by fractions of a percent to stay in step with the picture. See Accuracy for what is covered.
• Three demo games included. Night Flight (NES), Color Flight (GBC) and Pocket Flight (GB) are tiny original homebrew games built into Notcher, so there's something to play before you add your own. Click Try the demos in the empty Library.

Notcher doesn't include or download any commercial games. Only play ROMs of games you own.

Built-in games

• Hover to open. The notch grows sideways, then down, and the games fade in.
• Pick a page. For You shows today's challenge, the ROM you played last and your recent games. Library holds your ROMs; Action, Puzzle, Brain and Idle hold the built-in games. Resting on a page in the sidebar switches to it.
• Click to play. Click a game, or move to it with the arrow keys and press Return. Nothing starts just because the pointer passed over it, and a click that lands while the notch is still opening is ignored. If you'd rather start games by resting the pointer on them, pick On hover under Settings → Notch → Start a game: a ring of light around the tile then counts down, and moving away cancels it.
• Esc to leave. Esc closes the game and hands keyboard focus back to the app you were in. Clicking anywhere else does the same.
• Quit from the notch. The power button in the header asks once, then quits. Settings and the menu bar icon have a Quit button too.
• No Play button, no loading screen, no account.

The games

	Game	Controls
⚡ Action	Runner: synthwave endless runner with coins, drones and rising speed	space jump (hold for height) · ↓ slide
	Snake: smooth-moving snake; the arena closes in as you grow	↑↓←→
	Pong: an AI opponent that gets sharper each match you win. First to 5.	↑↓
	Breakout: tough bricks, power-ups (wide, multi-ball, slow, +life) and combos	←→ · space launch
	Invaders · new: 55 marching aliens, crumbling shields and a mystery saucer	←→ · space fire
	Astro · new: vector space rocks with drifting physics and hyperspace	←→ turn · ↑ thrust · space fire · ↓ warp
	Trails · new: light cycles against up to three AI riders that hunt you down	↑↓←→
	Arcade: a cabinet of six micro games (Flap, Dodge, Bullseye, Echo, Lander, Hop), one featured each day	tab switch game
🧩 Puzzle	Stack · new: falling blocks with hold, ghost piece, 7-bag, wall kicks and back-to-back bonuses	←→ · ↑ rotate · space drop · C hold
	2048: animated slides and merges, with 3 undos	↑↓←→ · U undo
	Gems · new: match three in 30 moves. Fours make line gems, L and T shapes make bombs, fives make stars	arrows + space, click or drag
	Sudoku · new: freshly generated puzzles with a unique solution, notes and three difficulties	arrows · 1–9 · F notes · ⌫ erase · mouse
	Mines: 20×8 field; the first click is always safe; chording supported	arrows · ↵ reveal · F flag · right-click
	Solitaire: Klondike with drag & drop, double-click to send home, undo and auto-finish	arrows · ↵ pick/drop · D draw · U undo
🧠 Brain	Lexi · new: guess the five-letter word in six tries	type · ↵ guess · ⌫ delete
	Typer · new: a 30-second typing test with live WPM and accuracy	type · space next word
	Reaction: wait for green, then hit space	space
	Four · new: four in a row against a negamax AI that searches deeper every time you win	←→ · space drop · mouse
🌱 Idle	Miner: keeps digging while you work; four upgrade tracks	space mine · ↑↓ ↵ upgrade
	Farm: crops grow in real time, from 30-second wheat to 45-minute starfruit	arrows · ↵ plant/harvest · tab seed

Keys that work everywhere: esc back to work · P pause · R restart · M mute · S share score card. In Lexi and Typer, letters type instead.

Around the games

• Daily challenge. Every player gets the same game, seed and target each day, drawn from 14 games. Completed days build a streak 🔥.
• Personal records. Best scores, run history and Today / This Week / All Time views for every game and micro game.
• 59 achievements. Speed Demon, Snake God, Flawless, Card Shark, Genius, Grandmaster, Back to Work (exit with Esc 100 times), Tourist (play all 20 games), Blow on the Cartridge (play one of your ROMs) and more. Each one unlocks with a Dynamic-Island-style toast.
• Share cards. After a run, S renders a 1200×675 score card, copies it to the clipboard and opens the share sheet.
• Live ticker. When the notch is closed, a small stat sits beside it: Miner coins counting up, crops ready on the Farm, or your daily streak.
• No account. You get an anonymous ID like PLAYER-7X42 and can add a nickname if you want one. Everything stays on your Mac.
• Works without a notch. On Macs without one, Notcher shows a small pill at the top of the screen that expands the same way.

Download

Download Notcher.dmg, open it and drag Notcher into Applications. It runs on macOS 14 Sonoma or later, on Apple silicon and Intel Macs. Every release is listed on the Releases page.

Release builds are signed with a Developer ID and notarized by Apple once signing is set up for the repository (see Releasing). If a release says it isn't signed, macOS blocks it the first time: open System Settings → Privacy & Security and click Open Anyway next to Notcher.

Build from source

Requirements: macOS 14 Sonoma or later, Xcode 16+ (Swift 5.9+).

git clone https://github.com/jeothecreator/Notcher.git
cd Notcher
make run          # builds build/Notcher.app, quits any copy already running, opens the new one

Updating. If you cloned before, git clone stops with "destination path 'Notcher' already exists", and cd Notcher lands in your old copy. Update it in place instead, or delete the old folder and clone again:

cd Notcher
git pull
make run

The build prints Building Notcher <version> (…) (the version comes from the VERSION file), and the version also appears in Settings and at the bottom of the menu bar menu. Versions from 0.2.0 on have ROM support: the sidebar has a Library page.

Other targets: make app (build only), make dmg (build/Notcher.dmg), make zip, make test.

To hack on it in Xcode, run open Package.swift, choose the Notcher scheme and press Run.

Releasing

The Release workflow builds a universal app, packs it into Notcher.dmg and publishes it as a GitHub release. It runs when you push a tag such as v0.2.0, when a pushed commit message contains [release] (it then publishes v plus the version in the VERSION file), or from the Actions tab (Release → Run workflow). A tag that doesn't exist yet is created; publishing an existing one again replaces its DMG, which is how you re-publish a release signed once the secrets below are in place.

To sign and notarize releases with your own Developer ID, add these repository secrets (Settings → Secrets and variables → Actions):

Secret	What it is
MACOS_CERTIFICATE	Your Developer ID Application certificate and private key, exported from Keychain Access as a .p12, then base64-encoded
MACOS_CERTIFICATE_PASSWORD	The password you chose when exporting the .p12
NOTARY_APPLE_ID	The Apple ID email of your developer account
NOTARY_TEAM_ID	Your 10-character team ID (Membership details)
NOTARY_PASSWORD	An app-specific password for that Apple ID

With the GitHub CLI, each command below prompts for its value, so secrets stay out of your shell history:

base64 -i DeveloperID.p12 | gh secret set MACOS_CERTIFICATE -R jeothecreator/Notcher
gh secret set MACOS_CERTIFICATE_PASSWORD -R jeothecreator/Notcher
gh secret set NOTARY_APPLE_ID -R jeothecreator/Notcher
gh secret set NOTARY_TEAM_ID -R jeothecreator/Notcher
gh secret set NOTARY_PASSWORD -R jeothecreator/Notcher

You can also sign on your own Mac without uploading anything: save your notary credentials once with xcrun notarytool store-credentials notcher, then run

NOTCHER_SIGN_IDENTITY="Developer ID Application: Your Name (TEAMID)" NOTARY_PROFILE=notcher make dmg

Notcher runs as a menu bar agent: no Dock icon, with a 🎮 icon in the menu bar for Settings and Quit. The global shortcut ⌃⌥⌘G opens the arcade with keyboard focus, and you can change it in Settings.

Mac App Store

Notcher is ready for the Mac App Store. It runs in the App Sandbox with a privacy manifest, and the App Store workflow checks on every [appstore] commit that the sandboxed build starts, works and quits cleanly. AppStore/README.md walks through what's left on Apple's side:

• the App ID, certificates and profile
• the App Store Connect record
• uploading and TestFlight

The listing text, review notes and screenshots are in AppStore/.

make sandbox                                                   # try the sandboxed version locally
APPSTORE_PROFILE=~/Downloads/Notcher.provisionprofile make appstore   # signed build/Notcher.pkg for App Store Connect
make appstore-shots                                            # re-render the App Store screenshots

How it's built

Sources/
├── NotcherCore/            Pure Swift (Foundation only), unit-tested on macOS and Linux
│   ├── Engine/             GameEngine protocol, input, seeded RNG, particles, geometry
│   ├── Games/              20 engines + 6 Arcade micro games, all deterministic state machines
│   ├── Emulation/          NES and Game Boy / Color emulators, ROM library, zip reader, demo cartridges
│   └── Meta/               Catalog, word lists, score book, stats, achievements, daily challenge, save file
└── Notcher/                The macOS app (AppKit + SwiftUI)
    ├── App/                Notch panel, window controller, hotkey, key mapping, app delegate
    ├── Arcade/             ArcadeController (notch state machine, launching, drops), GameSession
    ├── Console/            ROM sessions: emulation thread, frame pacing, audio, controllers
    ├── Services/           Sound synthesizer, save store, share cards, prefs
    ├── UI/                 Notch shape, launcher pages, game screen, trophies, settings
    └── Games/              Canvas / SwiftUI renderers for every game

• The notch is a borderless, non-activating NSPanel that sits above the menu bar on every Space, including over full-screen apps. The panel is transparent and passes clicks through everywhere except the visible notch shape. Notch size comes from NSScreen.safeAreaInsets and auxiliaryTopLeftArea / auxiliaryTopRightArea.
• Hover uses global mouse tracking, so it works while another app is active and needs no Accessibility permission. Focus: launching a game makes the panel key, and Esc re-activates the app you came from.
• Keyboard navigation in the launcher is spatial: arrows move to the nearest item in that direction, across the sidebar, header and grid, and tab flips pages.
• Game loop. A CADisplayLink ticks the active engine, which runs at 120 Hz on ProMotion displays. Engines emit events (sounds, stats, records, screen shake), and the app turns those into audio, achievements and personal records.
• Sound is synthesized at launch with AVAudioEngine. The app ships no audio files.
• Persistence is one JSON file in ~/Library/Application Support/Notcher/. Decoding is tolerant, so updates never wipe your progress. ROMs live next to it in Library/, with their battery saves, resume states and posters.
• Drag and drop. The panel normally lets clicks through, so it watches the drag pasteboard's types (never its contents) while a mouse button is held. When files are dragged near the notch it starts accepting mouse events there and shows the drop target.

Accuracy

The emulators are checked against the standard community test ROMs on every push (Scripts/fetch-test-roms.sh downloads them; they aren't stored in the repo):

Test	Result
Blargg cpu_instrs (Game Boy, all 11)	passes
Blargg instr_timing (Game Boy)	passes
Blargg mem_timing (Game Boy)	passes
Blargg official_only (NES, all 16)	passes
nestest (NES, every instruction against the reference log)	matches

Cartridge hardware:

• NES: NROM, MMC1, UxROM, CNROM, MMC3, AxROM, Color Dreams and GxROM (mappers 0, 1, 2, 3, 4, 7, 11 and 66), which covers most of the licensed library. Others are recognized and named when you add them.
• Game Boy / Color: ROM only, MBC1, MBC2, MBC3 (with its real-time clock) and MBC5, which covers nearly every game.

Screenshots

The images in this README are rendered by the app itself:

.build/release/Notcher --render-previews previews/

That command plays every game for a few seconds with a small autopilot, flies the demo cartridges through their emulators, and writes each notch state to a PNG. CI runs it on every push and attaches the results as the Notcher-previews artifact.

Tests

swift test

The core suite covers the emulators (CPU instructions and timing, PPU rendering, sprites, scrolling, mappers, save states, battery RAM, the demo cartridges end to end), the ROM library and zip reader, engine rules (Stack rotation, line clears and hold; Sudoku generation with a unique solution; Gems swaps and special gems; Lexi letter marking with repeated letters; Four's AI taking wins and blocking threats; 2048 merges; Mines flood fill and chording; Solitaire moves, undo and auto-finish), the economies (Miner offline income cap, Farm growth), score books, achievements, daily challenges and save compatibility. It runs on both Linux and macOS in CI.

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Hover. Click. Play. Esc. Back to work.