I personally feel that video game music can be very nice when you aren't playing the game and quite suitable for doing other things or just relaxing. I also enjoy listening to video game music done in different styles, there's a website that hosts monthly contents called "dwelling of the duels" where anyone can enter songs. Each month a topic is picked based around video games and users submit their renditions of famous video game songs, sometimes as joke entries that are hilarious but other times there's some really quality stuff like one month there was a 20 minute long metroid metal song called "crystal flash" that went through nearly all the themes from super metroid and it rocks my socks harder than some non-video game metal music. Also I have the track "HEAL" from the game ICO as my alarm clock ringtone that wakes me up each morning. It's a very soothing track with nice sounds that gives you a nice easy start into your day. Certainly, video game music works outside of video games. Maybe not all the time but then again, some non-video game music doesn't always fit where it's used either.