Vortex Sub is a native Android offline submersible bullet hell action game.
The core gameplay mechanics focus on continuous relative finger drag and micro-hitbox bullet evasion across deep trenches.

- Continuous relative touch drag controls translating the submersible without finger occlusion
- Micro-hitbox precision collision detection paired with outer graze aura ring
- Graze system registering near-misses and boosting combo multiplier up to 20x
- Combo decay meter displaying remaining time before multiplier tier decays
- Automated forward torpedo system targeting hostile deep-sea entities
- Abyssal Leviathan boss entity implementing 7 behavioral finite state machine states
- Procedural bullet generators producing geometric spiral barrages and radial ring blooms
- Dual-axis screen shake and haptic feedback triggered on hull impacts and depth milestones
- Acoustic Sonar Bomb ability clearing all active enemy bullets and converting them into bonus score points
- Three tactical power-ups: Sonar Shockwave, Phase Shield, and Chrono Current
- Dedicated hardware-accelerated SurfaceView rendering pipeline operating at 60 FPS
- Procedural tone and noise synthesizer generating sonar pings and impact bursts via AudioTrack
- Dedicated background audio thread playing synthesized deep-sea drone notes
- In-game heads up display reporting current score, depth descended, hull lives, and bomb count
- First-session interactive control tutorial explaining relative drag, grazing, and bomb controls
- In-game pause menu with resume, redeploy, and surface to menu buttons
- Stage victory screen with star ratings and final score calculations
- Defeat screen displaying final score achieved and deepest trench record score
- Settings menu with individual switches for sound effects, music, and haptic feedback
- How to play screen documenting evasion rules, graze mechanics, and power-up functions
- About screen displaying version number 20.20.20 and offline privacy notice
- Standalone offline execution storing session data in memory without internet access