Your home has become a portal for zombies and other creatures to enter as part of the Demon King's army bent on destroying the earth. Your only weapon is a mystical hammer which use can use to fight the monsters which stalk you both on ground and from the air.
HoloWeen Adventure takes advantageous of spatial mapping. As you walk around, a spatial graph is continuously created allowing the monsters to become more and more intelligent in their ability to stalk you. The game can be played indoors but is great in a large space and even outdoors under good light conditions (not too sunny).
The game is scary in an "Alfred Hitchcock" style. There are no blood and guts but hearing the monsters stalking you and hearing screams when you are attacked, will make your heart race. I'd guess that the game could give young children nightmares so best to be played by those a bit more mature and able to recognize that this is just a game even though it is happening in augmented reality and seems real.
The game is free to play and there is a paid version which enables you to continue games (after being defeated by monsters). This is quite helpful in getting to the higher levels and being able to defeat the Demon King. The paid version is also helpful for enabling me to continue to make these games so please consider it if you find the game entertaining.