Games made for smartphones; a broad term covering casual games to full-fledged RPGs and competitive titles, commonly used in conversation.
通勤中にスマホゲームをする人が増えた。
More people play smartphone games during their commute.
最近のスマホゲームは課金要素が強く、注意が必要だ。
Recent smartphone games often have strong microtransaction elements, so be careful.
友達とスマホゲームで協力プレイを楽しんだ。
I enjoyed cooperative play with friends in a smartphone game.
彼はスマホゲームの開発に興味があると言って、プログラミングを学び始めた。
He said he's interested in developing smartphone games and started learning programming.