升级：卡牌游戏

Tractor: Card Game is a four-player card game based on the classic Chinese game Tractor (Sheng Ji / Upgrade). Players team up in either the North–South or East–West partnership and compete using two decks of cards. The game features strategic elements such as declaring trump, overriding trump, exchanging the kitty, throwing multiple cards, playing tractors, capturing points, and scoring from the final trick. The game supports both single-player matches against AI opponents and local network multiplayer. With smooth dealing animations, card-playing sound effects, game history, and detailed end-of-round results, every match combines the strategic depth of traditional Tractor with a polished and fluid mobile gaming experience.