Losing sleep over this

I feel like a bad parent. I have an almost 3 year old. Mind you he actually like he’s 4 and pretty advanced but anyway a month or so ago he was into the song chicken jockey from Minecraft and he likes how those green things looked. I think he saw a clip or two from the movie and got really into those green things. I usually get into all his interests and I knew this was a video game but he obviously doesn’t know that so I just went along with it and we got a Minecraft book for him to read. I feel like it’s kind of violent and maybe just he’s too young and now I feel like I failed him. Thankfully he is onto another obsession so I think he got over this and it only lasted like one month but I feel like a terrible horrible mom. Also just a side note, he’s into spiderman and pretend fights and plays with my husband. I’m kind of embarrased by this because I feel like it’s opening him up to violence. I know he’s a boy but I don’t like it