《老鼠小子》（Mappy Kids / マッピーキッズ）是由Namco 於 1989 年 12 月 22 日在任天堂 Famicom（紅白機）上推出，《貓鼠大戰》系列的第三作，也是整個系列風格變化最大的一款。不同於前兩代的「警匪追逐」核心玩法，轉型為橫向捲軸平台動作遊戲，並加入經營建設與競爭對抗元素，是系列中唯一強調「成家立業」概念的作品，玩法豐富多元，兼具溫馨的策略競爭感。

在視覺與設計上，採用明亮、飽和的色彩，角色比例更大，整體呈現出精緻的週六晨間動畫風格。可以選擇控制 Mappy 的兩個兒子——穿藍衣的 Happy 或穿紅衣的 Rappy，並且遊戲支持雙人對戰模式，這在當時相當受歡迎。玩法跨越多種類型，不僅包括傳統平台跳躍，也加入小遊戲元素以及房屋裝潢模擬，使操作策略性和趣味性大幅提升。

故事劇情充滿生活氣息，Mappy 的兩個兒子都愛上可愛的老鼠姑娘 Piky。父親告訴他們，誰能蓋出最漂亮、最豪華的房子，誰就能贏得 Piky 的芳心。於是兄弟倆展開一場跨越森林、城鎮與工廠的冒險，必須在關卡中一邊闖關，一邊收集掉落的金幣，最終利用這些資金購買家具與裝修材料，打造夢想之屋。每一關的收集行動都直接影響最後的房屋建設成果，使策略與冒險緊密結合。

操作上，相較前作有顯著變化。玩家不再只是逃跑，而可以用踢擊攻擊敵人或打開寶箱，跳躍手感靈活流暢。關卡中充滿金幣和錢袋，需要盡可能收集，以便在關卡結束後進行購屋操作。每一關還會有小遊戲對決，如找不同、連連看或賽跑，贏家可獲得額外資金或直接奪取對手的財產。購物與裝修系統是遊戲最迷人的部分，可以購買壁紙、屋頂、電視、鋼琴甚至跑車，隨著關卡推進，房子會逐步變成豪華宅邸。

在市場上獲得「創意十足、極具重玩價值」的評價。評論家讚賞遊戲將動作冒險與生活模擬巧妙結合，看著破舊小屋逐漸變成豪宅，給玩家極大的成就感。雙人模式的設計也非常刺激，可以搶奪對手財產，增添緊張的競爭樂趣。歷史地位上，是 Namco 對《Mappy》品牌的一次大膽延伸，它成功將系列角色塑造得更加有生命力，即便脫離原本的蹦床玩法，也依然保有獨特魅力。 這款遊戲最經典的回憶莫過於「在關卡中辛辛苦苦攢了一大筆錢，卻在最後的小遊戲對決輸給對手，看著心愛的鋼琴被搬走」。許多玩家也記得為了贏得 Piky 的青睞，努力在房子中塞入昂貴家具的那段緊張又溫馨的時光。

“Mappy Kids” (マッピーキッズ), released by Namco on December 22, 1989 for the Nintendo Famicom, is the third installment in the Mappy series and represents the biggest stylistic shift in the franchise. Unlike the first two games, which centered on the classic police-and-thief chase, this entry transformed into a side-scrolling platformer while introducing elements of property management and competitive play. It is the only game in the series to emphasize the theme of “building a home and starting a family,” offering a rich, multi-layered gameplay experience that combines adventure, strategy, and a warm, competitive charm.

Visually and stylistically, the game adopts bright, saturated colors and larger character sprites, evoking the feel of a polished Saturday morning cartoon. Players can control one of Mappy’s two sons: Happy, in blue, or Rappy, in red. The game also supports a two-player competitive mode, which was particularly popular at the time. Its gameplay spans multiple genres, combining traditional platforming with mini-games and home-decoration simulation, greatly enhancing both strategy and fun.

The storyline carries a charming domestic narrative. Both Happy and Rappy fall in love with the cute mouse Piky. Their father tells them that whoever can build the most beautiful and luxurious house will win her heart. This sets the stage for an adventure across forests, towns, and factories. Throughout each level, players must navigate obstacles, collect coins, and ultimately use these resources to purchase furniture and decorations, gradually building their dream home. Every item collected during the levels directly impacts the final house, tightly linking strategic planning with adventure gameplay.

Gameplay mechanics saw significant changes from previous entries. Players are no longer limited to fleeing enemies; they can now kick to attack foes or open treasure chests, and jumping feels responsive and fluid. Levels are filled with coins and money bags, which must be collected to fund home construction after each stage. At the end of each level, mini-game competitions—such as spot-the-difference, matching, or racing—determine additional rewards, with winners gaining extra funds or even stealing assets from their opponent. The shopping and decoration system is the game’s highlight, allowing players to buy wallpaper, roofs, TVs, pianos, and even sports cars. Over the course of the game, the house gradually evolves into a luxurious mansion.

“Mappy Kids” received high praise for its creativity and replay value. Critics applauded its clever combination of action-adventure and life simulation, noting the satisfaction of watching a dilapidated house transform into a magnificent mansion. The two-player competitive mode added thrilling tension, allowing players to directly interfere with each other’s progress. Historically, it stands as a bold extension of the Mappy brand, giving the series’ characters greater vitality while maintaining charm, even as it moved away from the original trampoline-based gameplay.

One of the game’s most memorable moments comes from the tense yet heartwarming experience of “carefully collecting a fortune in coins during a level, only to lose the final mini-game and watch your beloved piano get taken away.” Many players also fondly recall the challenge of trying to impress Piky by filling their house with the most expensive furniture, making for a uniquely engaging and cozy adventure.