OpenGame: Open Agentic Coding for Games. - Yilei Jiang; Jinyuan Hu; Qianyin Xiao; Yaozhi Zheng; Ruize Ma; Kaituo Feng; Jiaming Han; Tianshuo Peng; Kaixuan Fan; Manyuan Zhang; Xiangyu Yue 001 (CoRR, 2026)