All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad, is His slave and Messenger.
Playing online video games with a non-Mahram (marriageable) girl, even if it does not involve what could lead to Fitnah (temptation), like chatting with her and the like, is still unsafe and risky. It may lead to talking to her, and things might take a more serious turn. You should beware of that peril, take precautions to guard your religiosity, and be keen on the preservation of honor.
It should be noted that the permissibility of playing video games is conditional upon their being free of prohibitions, such as images that are forbidden to look at, music, and the like. Moreover, these games must not distract and preoccupy a person’s time and distract him from performing the prayers on time. All these are risks that should be heeded.
Moreover, a believer should be keen on filling his time with useful deeds that benefit him with regards to his religion and his worldly life. Verily, time is among the most valuable assets a believer has and one of the greatest blessings conferred by Allah, The Exalted, upon him. It is narrated on the authority of Ibn ‘Abbaas, may Allaah be pleased with him, that the Prophet said: “There are two blessings concerning which many people are losers (fail to take advantage of): health and free time.” [Al-Bukhari]
Allah Knows best.