YOU SAID:

John and I are going to play the game to play the game Mario

INTO JAPANESE

ジョンと私はマリオのゲームをプレイするつもりです

BACK INTO ENGLISH

John and I are going to play a Mario game.

INTO JAPANESE

ジョンと私はマリオのゲームをするつもりです。

BACK INTO ENGLISH

John and I are going to play a Mario game.