Games played on mobile phones (feature phones or smartphones); today largely overlaps with 'smartphone games'.
通勤中に携帯電話ゲームで短い時間だけ遊ぶ人が多い。
Many people play mobile phone games for a short time during their commute.
昔は携帯電話ゲームといえばフィーチャーフォン向けのものが主流だった。
In the past, mobile phone games mainly meant titles for feature phones.
この携帯電話ゲームはデータ通信量が多いので注意して遊んでください。
This mobile phone game uses a lot of data, so be careful when playing.