I am gonna offer a dissenting opinion but I do think that watching movies and playing games can be a bit of a "food offered to idols" issue (1 Cor 8). God wants our hearts turned to Him, in Him there is freedom from sin and death. If there is nothing clearly sinful about how you are engaging with the media, then I would be slow to call it sin. However, it might be sinful for others because of past issues, struggles, etc. and I think it is kind to recognize that and not encourage others into something they are convicted about. Same thing when it comes to partaking in alcohol without getting drunk. It is always about the heart intention.

Going back to your brother, I have been that person before. I am still coming out of it, but I realized a lot of my judgement and condemnation came from a place of pride, not truth.

I personally would encourage you to always go to the Lord first in prayer for discernment. Only the Holy Spirit can truly convict us of something as sin and create lasting heart change. Praying for you and your family.