The Last Carrot

A small, self-contained lane tower defence game for Android. Hungry critters march down the garden path and there is one carrot left. Build towers, upgrade them, hold the line.

中文說明

No permissions. No ads. No trackers. No network access. No bundled assets.

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What makes it unusual

There are effectively no asset files in this repository. Everything you see and hear is produced by the app itself:

• Audio is synthesised at runtime. On first launch the app generates sixteen sound effects and an eight-bar chiptune loop from oscillators and noise, writes them to its cache as WAV, and plays them back. There is not a single .wav or .ogg in the repo.
• Graphics are drawn, not loaded. The map, towers, HUD and menus are Canvas drawing calls; the units are system emoji; the launcher icon is a vector drawable.

The point is not minimalism for its own sake — it means there is no third-party content to license, attribute or get wrong.

Gameplay

Twenty levels across five chapters, each chapter with its own palette and its own new problem. Pick a chapter, then follow a winding trail of levels; every stop you have cleared keeps its star rating. Levels unlock in order, and stars are awarded on how much carrot you have left.

Eight towers, unlocked gradually — each arriving just before the enemy it answers:

Tower	Cost	Role
🏹 Arrow	50	Fast single target
❄️ Ice	60	Hard slow, one target at a time
💣 Bomb	85	Splash damage
🌙 Moon	75	Wide, gentle slow across a whole group
☠️ Poison	95	Damage over time, ignores armour
🚀 Rocket	120	Flies straight and pierces everything on the line
⚡ Tesla	130	Chain lightning between nearby enemies
☀️ Sun	110	Pulses damage in a ring around itself

Each tower upgrades three times, refunds 65% when sold, and can be told whether to target the enemy that is furthest along, the strongest, or the nearest. Each level offers only four or five of your towers, so the same roster produces different puzzles.

Five enemy types — ordinary thieves, fragile sprinters, huge swarms, armoured ironhides, and garden overlords that take a serious bite out of the carrot if they get through.

Breakable obstacles. Rocks, trees, mushrooms, ice blocks and crates sit around the map. Tap one to mark it and your towers chip away at it only while no enemy is in range, so clearing never costs you a leak. Breaking one pays gold and frees the tile to build on. Sun, Moon and Rocket damage obstacles on their own.

Also: 1x/2x/3x speed control, call waves early for bonus gold, drag to position a tower and see its range before committing, and automatic saving so you can stop mid-wave.

Building

Requirements: JDK 17 and the Android SDK (compileSdk 34).

The Gradle wrapper is committed, so you do not need Gradle installed:

./gradlew assembleDebug

The APK lands in app/build/outputs/apk/debug/app-debug.apk. If you already have Gradle 8.2 or newer, gradle assembleDebug works too — that is what CI does.

Use JDK 17, not a newer one: Gradle 8.2 only runs on Java 19 and below. Raising the wrapper to Gradle 8.5+ would lift that limit.

About the wrapper JAR. CI validates it against Gradle's published checksums, so it has to be an official build. If you regenerate it, run the wrapper task from an official Gradle distribution — the gradle package shipped by Linux distributions is often an old repackaged build whose checksum will not match, and the build will be rejected.

Project layout

Everything lives in app/src/main/java/io/github/acidefluorhydrique/carrot/. There is no dependency injection, no architecture framework and no third-party library beyond AndroidX core and appcompat — a SurfaceView with a game thread, and plain classes.

File	Responsibility
GameView, GameThread	Game loop, screen routing, touch handling
GameLevel, Chapter	Level and chapter data, difficulty curve, themes
Tower, TowerManager, Bullet, PiercingShot	Towers, targeting, projectiles
Enemy, EnemyManager, EnemyKind	Enemies, waves, spawning
Obstacle, ObstacleManager	Breakable props
SoundEngine	Runtime audio synthesis
Effects	Particles, floating text, screen shake
MenuRenderer, HudRenderer, Widgets	All UI drawing
GameSave	Persistence
Strings, LocaleManager, Ui	Localisation and density-independent sizing

Level data is generated by a script that applies a smooth difficulty curve and validates every path for connectivity, self-intersection and buildable space, then emits Kotlin. Hand-editing GameLevel.kt works, but regenerating is easier if you want to reshape the curve.

Translating

The interface ships in English, Traditional Chinese and Simplified Chinese, switchable in-game and independent of the system language.

To add a language, copy app/src/main/res/values/strings.xml into a new qualified directory and translate the values. Script-based qualifiers are used for Chinese so that Hong Kong and Macau fall back correctly:

app/src/main/res/values/               English (default)
app/src/main/res/values-b+zh+Hant/     Traditional Chinese
app/src/main/res/values-b+zh+Hans/     Simplified Chinese

Two rules matter: keep the string keys identical across every locale, and keep the positional format arguments (%1$d, %2$s, …) consistent — a translation that drops or renumbers one will crash at runtime. Then add your locale to LocaleManager.options so it appears in the in-game picker.

Licence

GPL-3.0-or-later. See LICENSE. Source files carry SPDX headers.

Not affiliated with anything

This is an original game. It borrows nothing but the genre from the lane tower defence games that inspired it, and is not connected to, endorsed by, or derived from any commercial title.