It was in the back of a used bookstore, under something else. Was reading it at a rather tough time in my life. So I have fond memories of the thing.
It does have a full game, more or less, but the rules are so scattered throughout I'm not sure if anyone's ever played it. There are, in fact, stats for God (though apart from being level 24 and having a 40 intelligence and rank in host 9 with resistance to appeal 7 we have no stats on Him--though we're told his areas of interest and patronage are creation and dominance, disfavor is rebellion, and "Three persons, Can operate independently"), the Virgin Mary, various angels and saints, and the devil ('Lucifer') and a bunch of demons. There's a whole system of correspondences with each one corresponding to one of the twelve zodiac signs (both God and the Devil), which also affect statistics and spells, and a few varieties of magic-users in a rough sort of status hierarchy from Cabalists through Wizards and Witches down to cunning men/wise women. Fighters seem to be chosen from a list of historical soldiers--it's not clear. It has the Norse deities too. There are miniatures rules for combat as well as gaining levels in adventuring--it doesn't seem to know whether it wants to be a miniatures wargame or a tabletop RPG.
There are some fun monsters that didn't make it into the Monster Manual, like the Bonnacon (which has a huge explosive farts) and the Singing Bone (which is what it sounds like), and a bunch of others like dwarves and giants with a more mythologically Celtic or Anglo-Saxon feel than the D&D varieties.
I really enjoy it, honestly. It's loopy and hints at a more chaotic era of gaming, and there's certainly stuff you could mine for your own campaign.
There are a bunch for about $10-30 on Abebooks, and Amazon sells them used for about $30-50. I have no idea who holds the copyright at this point. Galloway's dead, sadly, so I wish someone would stick it in the public domain, but I guess it went to Stein and Day, but they're now bankrupt (their bankruptcy being the subject of the book A Feast For Lawyers), so....no clue? Any surviving relatives?