Milk Orbit

A native iPhone and iPad gravity puzzle game: place black holes, collect the beacons, and guide your ship to the dock across 20 sectors. Built with Swift, UIKit, and Core Graphics, with a deterministic game core and no third-party game engine.

Build and run

Use Xcode 27.2 with its iOS 27.2 SDK on macOS. The deployment target is iOS 17.0, but compiling the current source requires newer UIKit declarations, including iOS 27.1 reserved-region APIs. Runtime availability checks provide fallbacks on older supported iOS versions. The package uses Swift 6.

Select Xcode in its Settings → Locations → Command Line Tools, or use DEVELOPER_DIR to select your installation. Install an iOS 17 or later Simulator runtime and Python 3 for the run helper, then run these commands from the checkout root:

bash scripts/check.sh --core
bash scripts/run-simulator.sh

The first command validates the project and runs core tests. The second builds, installs and launches an unsigned app in an iPhone Simulator; pass an optional Simulator UUID to choose a destination. It restarts the app on that destination. Use bash scripts/build-ios.sh for a build without device actions, or Xcode for an iPad destination.

You can also open MilkOrbit.xcodeproj, select the shared MilkOrbit scheme and an installed Simulator, and Run. Simulator builds do not need a development team. For a physical device, copy Config/Local.xcconfig.example to the ignored Config/Local.xcconfig and supply your own team and bundle identifier.

For core-only development with a Swift 6 toolchain on macOS or Linux:

swift test

There is currently no automated UI test suite. Core tests and a successful build do not establish that gameplay, layout, or haptics work correctly; see CONTRIBUTING.md for manual checks.

GitHub Actions defines Linux core tests and an unsigned macOS Simulator build. The macOS runner must have Xcode 27.2 or later installed; manual workflow runs accept its Contents/Developer path. The build fails with a clear SDK requirement when the runner's default Xcode is older. Hosted CI has not been verified during local preparation.

Play

• Tap empty board space to place a hole. If controls are open, the first tap closes them.
• Tap a hole to adjust its strength in 0.5 steps, move it, or remove it. Hold +/− to repeat. Hold and start vertically to adjust strength; start sideways to move on the grid, or use Move before dragging.
• Launch begins flight. Hold 4× to speed up simulation; release for 1×. Abort returns to editing. Undo restores edits, and Reset clears the board.
• Collect the diamond beacons, avoid solid obstacles and hole cores, then reach the teal dock. The previous flight trail stays visible while planning a retry.
• Help offers a supplied solution and a haptics mute option. VoiceOver provides placement, adjustment, movement, removal, and flight-speed actions. Portrait and landscape share the same game state.

Project layout

• Sources/OrbitCore: physics, campaign state, layout rules, and bundled sectors.
• Sources/MilkOrbitApp: UIKit app, rendering, input, haptics, and artwork.
• Tests/OrbitCoreTests: core regression tests and reference fixtures.

License and credit

MIT. Based on Hole Punch by notoriousbfg.

Silkscreen retains its SIL Open Font License; the Milk carton retains its original MIT license.