Game User Interface (UI) implementation involves translating highly stylized mockups into interactive engine entities. However, current "Screenshot-to-Code" tools typically assume standard rectangular layouts, failing to address the irregular geometries and deep visual hierarchies characteristic of game interfaces. To bridge the semantic gap between pixels and code, we introduce SPRITE, a novel pipeline that rapidly transforms static screenshots into editable engine assets. By integrating Vision-Language Models (VLMs) with a structured YAML intermediate representation, SPRITE explicitly captures the complex container relationships essential for game layouts. We evaluated SPRITE against a newly curated Game UI benchmark and conducted expert reviews with professional developers, assessing its reconstruction fidelity and prototyping efficiency. Our findings indicate that SPRITE streamlines implementation by eliminating tedious coding and resolving complex nesting via its intermediate representation, thereby empowering rapid in-engine iteration. This effectively blurs the boundaries between artistic design and technical implementation in game development.