This is a weird one. I stumbled over this artist known as Yamasa Sound Team, and found a bunch of anime looking art. I took a peak over at Game-ost.com and discovered that yes indeedy, these people make game music. But I have never heard about this stuff.
I did some searching, and it seems it is mostly soundtracks for Japanese Pachi-Slot games. Since I don't speak Japanese my ability to research these guys is very limited. All i know is that these things seem to be soundtracks for specific versions of their Pachi-slot games, and they are on Spotify, so they quality for a blog post.
Pachi-Slot Cyber Dragon2
Pachi-Slot Moeyo Kung Fu Taisen