Oh wow, this one is in a league of its own. Marvellous entry.
I don't wan't to fall into sycophancy but I love everything about it. The interpetation of the theme, the visuals, the description of each eldritch abomination, the surprisingly deep gameplay.
I'm not sure I agree with the other commenters that the game need a tutorial. Most gameboy game never got one and were expected to be played alongside their instruction manual : I think that's what the game lacks. A detailed explanation of relics, prayer, and influence spread on your itch page would do wonder for your onboarding and would preserve the "gameboy soul" a lot better.
After trying things for a while everything comes together tho. You spread to get more towns which in turn give you more actions. You pray to charge your power, you search to get more relics. Pretty nice variety of relics by the way, I was impressed to see that they were not merely simple bonuses and that each had its unique sprite.
A thing that would have probably helped with your visibility problem would have been to add unique rune to each god and display it above their controlled towns.
Amazing job anyways, always a joy to see a fellow Gamemaker user.