CrystalEngine is a full-featured, cross-platform game engine with an integrated editor, built from scratch in C++. It features a custom Vulkan/Metal rendering backend with a directed acyclic frame graph for render pass scheduling, a physically-based rendering pipeline with IBL and shadow mapping, and a modular architecture with dynamic module loading. The engine includes a comprehensive asset pipeline (import, compression, serialization), a job system for parallelism, and a physics integration via Jolt. A notable aspect is the dual UI framework: the older CrystalWidgets (CSS-styled) and the newer Fusion framework (declarative, property-based), both used in the editor. The editor provides dockable windows, property editors, material editing, scene outliner, and asset browser. The codebase demonstrates strong engineering with clean abstractions (RHI, RPI, frame graph, job system) but shows signs of ongoing migration (two UI frameworks) and some incomplete features. It is actively maintained and suitable for learning or extending a modern game engine architecture.