# Engine systems Use the [status and compatibility reference](https://rustic-game-engine.pages.dev/markdown/reference/compatibility.md) to distinguish implemented systems from planned workflows. Each system guide retains its detailed API and limitations. | System | Start here | API reference | | --- | --- | --- | | Rendering / scene lighting | [Sky and atmosphere](https://rustic-game-engine.pages.dev/markdown/guides/scene-environment.md), [Rendering System](https://rustic-game-engine.pages.dev/markdown/open-source/engine/rendering-system.md) | [Environment](https://rustic-game-engine.pages.dev/markdown/api/environment.md) | | Primitive physics | [Basic physics](https://rustic-game-engine.pages.dev/markdown/guides/physics.md) | [Queries and forces](https://rustic-game-engine.pages.dev/markdown/api/physics-actions.md) | | Animation | [Imported clips](https://rustic-game-engine.pages.dev/markdown/guides/gameplay-actions/imported-animation.md), [Layering](https://rustic-game-engine.pages.dev/markdown/guides/gameplay-actions/animation-layers.md) | [Animation](https://rustic-game-engine.pages.dev/markdown/api/animation.md) | | Tweening / easing | [Animate properties](https://rustic-game-engine.pages.dev/markdown/guides/gameplay-actions/properties.md) | [Tween](https://rustic-game-engine.pages.dev/markdown/api/tween.md), [Ease](https://rustic-game-engine.pages.dev/markdown/api/ease.md) | | Paths / movement | [Follow a path](https://rustic-game-engine.pages.dev/markdown/guides/gameplay-actions/paths.md) | [Path](https://rustic-game-engine.pages.dev/markdown/api/path.md), [Movement](https://rustic-game-engine.pages.dev/markdown/api/movement.md) | | Audio | [Play, fade and record](https://rustic-game-engine.pages.dev/markdown/guides/gameplay-actions/audio.md) | [Audio](https://rustic-game-engine.pages.dev/markdown/api/audio.md) | | Input | [Held keys in Play](https://rustic-game-engine.pages.dev/markdown/scripting/lua/input.md) | [Input](https://rustic-game-engine.pages.dev/markdown/api/input.md) | | Cameras | [Cameras and lights](https://rustic-game-engine.pages.dev/markdown/guides/cameras-and-lights.md) | [Current camera](https://rustic-game-engine.pages.dev/markdown/api/camera.md), [Camera actions](https://rustic-game-engine.pages.dev/markdown/api/camera-actions.md) | | Events / timers / clock | [Gameplay actions](https://rustic-game-engine.pages.dev/markdown/guides/gameplay-actions.md) | [Events](https://rustic-game-engine.pages.dev/markdown/api/events.md), [Timer](https://rustic-game-engine.pages.dev/markdown/api/timer.md), [Clock](https://rustic-game-engine.pages.dev/markdown/api/clock.md) | | UI script assets | [HTML/CSS](https://rustic-game-engine.pages.dev/markdown/scripting/web.md) | [JavaScript behavior API](https://rustic-game-engine.pages.dev/markdown/scripting/javascript/api-reference.md) | Current HTML support does not implement rendered layout, a DOM or network access. HTML-based game UI with CSS styling is planned; see the Web guide for current behavior. The public [hosting-sdk](https://rustic-game-engine.pages.dev/markdown/open-source/hosting-sdk.md) is **Not Yet Implemented**; there is no documented multiplayer or managed-hosting SDK workflow to follow. [Standalone](https://rustic-game-engine.pages.dev/markdown/building/publishing.md) is a local Play mode, not a completed export target.