A lot of indie games never ship. Not because the developers lack skill, but because the scope grows, the timeline stretches, and enthusiasm fades before the submission button gets clicked.
This guide takes a different approach: constrain the scope ruthlessly, use Antigravity AI for the implementation work that would otherwise cause you to get stuck, and ship something real within 90 days. Your first game doesn't need to be great — it needs to be finished.
Why 90 Days?
Game development has a natural tendency to expand. There's always one more feature to add, one more thing to polish. A 90-day constraint forces decisions that actually help:
- It requires you to define what the game is before you can start
- It makes weekly progress visible and measurable
- It delivers the experience of shipping before motivation runs out
The developers who build successful indie careers almost universally describe their first releases as small, flawed, and invaluable. The experience of going through the entire process — and surviving it — is the thing worth getting.
Day 0: Define the Game and Configure Your Antigravity Project
The One-Sentence Test
Before writing a single line of code, define your game in one sentence. If you can't, the scope is too large.
Working one-sentence concepts:
- "A vertical scrolling shooter where you collect power-ups to defeat increasingly fast enemies"
- "A tap-to-jump character that dodges obstacles as they come faster over time"
- "A color-matching puzzle where you merge blocks of the same color to clear the board"
If your concept requires a paragraph to explain, cut features until it fits in a sentence.
Choosing Your Stack
For mobile games, three options work well with Antigravity:
Unity + C#: Best support, most documentation, strongest Antigravity integration. Recommended if you're new to game development.
React Native + Expo: Strong choice for casual games, puzzle games, or anything with a simple UI-driven interaction model.
Godot + GDScript: Free, open source, excellent for 2D games. Growing ecosystem with decent Antigravity support.
Start your first Antigravity session with context:
I'm building a 2D mobile game using Unity 2025 LTS.
Game concept: [your one-sentence description]
Target platforms: iOS and Android
Input: tap only (single touch)
My experience: basic C# understanding, new to Unity
My goal is to ship to App Store and Google Play within 90 days.
Give me a prioritized list of what to build in the first two weeks to
establish the core game loop.
Phase 1 (Days 1–30): Complete the Core Mechanic
The entire focus of the first 30 days: get the core game loop working. Graphics, sound, and polish come later.
Days 1–7: The Prototype
The prototype goal is simple: a version you can technically call a game.
What to build this week:
- Character movement
- Core input mechanic (tap, swipe, etc.)
- Basic collision detection
- A simple score counter
- Three scenes: title → gameplay → game over
Sample prompt for your first implementation session:
I'm building a tap-to-jump mobile game in Unity with C#.
Please implement:
1. A character that automatically moves left to right across the screen
2. A jump mechanic triggered by screen tap (Space bar for testing)
3. Obstacles (pipes) that scroll from right to left
4. Collision detection that triggers game over
5. A score that increments over time
Start with the PlayerController script.
Days 8–14: Game Feel Tuning
Once you have a playable prototype, play it yourself every day and take notes. What feels wrong? What's frustrating? What's almost fun?
Work with Antigravity on:
- Movement speed and gravity tuning
- Difficulty curve (starts easy, gets progressively harder)
- One simple bonus mechanic if the core loop supports it
Days 15–30: Complete the Core Loop
By end of day 30, you need:
- A working high score saved to device (PlayerPrefs is fine)
- Functioning restart flow
- Clear game over state with emotional impact (screen shake, sound)
- Basic audio (even placeholder sounds)
Do not add at this stage: detailed art, extra stages, settings menus, social features, monetization.
Phase 2 (Days 31–60): Polish and Content
With a working core, the second month is about making the game worth playing.
Days 31–45: Visual and Audio Assets
Where to find free assets:
- Unity Asset Store (filter by free)
- itch.io game assets section
- Kenney.nl (high-quality, free, commercial-use CC0 assets)
- Freesound.org (sound effects)
- OpenGameArt.org (music and sprites)
Tell Antigravity what you've acquired and get help integrating it:
I've downloaded a character sprite sheet with 4 frames each for:
- idle animation
- running animation
- jump animation
- death animation
Help me set up Unity's Animator component to switch between these states
based on the player's current action. Include the state machine setup
and the C# code to trigger transitions.
Days 46–60: One Retention Feature
Add exactly one feature that makes players want to return. Not two — one.
Options that work well without scope creep:
- Daily challenge mode with a fixed seed
- Achievement badges (first time past 100, 500, 1000 points)
- Cosmetic unlocks (new color or skin at score thresholds)
Using the existing score system, implement an achievement that displays
a "High Achiever" badge when a player first scores over 500 points.
Store the achievement state in PlayerPrefs so it shows only once.
Design the badge as a simple UI panel that auto-dismisses after 3 seconds.
Phase 3 (Days 61–90): Test, Optimize, and Submit
Days 61–70: Real Device Testing
Simulator testing isn't enough. Get your game onto physical devices as early as possible.
What to check on real hardware:
- Frame rate (target 60fps on mid-range hardware)
- Touch responsiveness (does it feel immediate?)
- Heat generation during extended play
- Layout on different screen sizes (small iPhone vs. large Android)
When reporting bugs to Antigravity, include precise reproduction steps:
Bug found on iPhone 16 during real device testing.
Steps to reproduce:
1. Start the game
2. Achieve a score over 300
3. Press home button to background the app
4. Return to the app
5. Score resets to 0
The score should persist through app backgrounding.
Please fix this and explain why it was happening.
Days 71–80: Performance Optimization
On an iPhone 12 (A14 Bionic), frame rate drops below 50fps when
more than 10 enemies are on screen simultaneously.
Help me:
1. Identify likely bottlenecks using Unity Profiler
2. Understand what to look for in the CPU and GPU sections of the profiler
3. Implement object pooling for the enemy spawn system
4. Reduce draw calls using sprite atlases
Start with the Profiler walkthrough.
Days 81–90: Store Submission
App Store Connect Text
Create App Store listing text for the following game:
Game name: [name]
Genre: Casual
Core mechanic: [your one-sentence description]
Key features:
- [feature 1]
- [feature 2]
- [feature 3]
Generate:
1. Full description (under 4000 characters, engaging and benefit-focused)
2. Subtitle (30 characters max)
3. Keywords (100 characters max, high-search-volume terms for this game type)
Provide both English and Japanese versions.
Required Screenshots
App Store requirements:
- 6.9-inch display (required)
- 6.5-inch display (recommended)
- 6.1-inch display (recommended)
Google Play requirements:
- Feature graphic: 1024×500px
- Minimum 2 screenshots
Privacy Policy
Both stores require a privacy policy URL:
Generate a privacy policy for a mobile game with these data practices:
- High scores: stored locally on device only
- Advertising: uses AdMob (collects advertising ID)
- Crash reporting: Firebase Crashlytics
- No user accounts or registration
- No collection of personal information
Format as Markdown. Provide English and Japanese versions.
Common Failure Patterns to Avoid
Scope creep: "Just one more feature and it'll be ready." Counter it by maintaining a "version 2 list" — when a new idea surfaces, write it down and don't add it to the current version.
Asset paralysis: "I'll start polishing when the art is better." Counter it by keeping placeholder art throughout development and swapping real assets in during Phase 2.
Perfectionism: Clean code matters, but not more than shipping. Use Antigravity to generate working code, ship, then refactor. You can ask Antigravity to note refactoring priorities in comments for future cleanup.
Rejection fear: App Store rejections are usually fixable minor issues. Common reasons include privacy policy problems, missing required metadata, or performance below Apple's threshold. None of these are catastrophic — they just require a resubmission.
The Most Important Thing
Antigravity AI dramatically reduces the number of times you'll get stuck during development. It can generate implementations, debug errors, and explain unfamiliar APIs quickly and accurately.
But it can't decide what your game is, playtest it with genuine curiosity, or click submit when you're anxious about whether it's ready.
Those decisions are yours. And making them — completing the loop from idea to shipped product — is the skill that actually matters in indie game development.
Ninety days from now, your game can be in the store. That experience changes how you see the next idea.