The Barrows Hunger

From itch.io:

In the Viridian hills, a cluster of silent mounds in the earth. They wait. Their dark mouths gape patiently, daring trespass. Ancient burial sites of some long lost order whose greatest wonders would never stand up to modern marvels. A cheap haul for a fledgling tomb robber, if anything still exists worth stealing from these humble monuments. They seem identical to a thousand other forgotten places burrowed in the earth like forgotten beetles.

They are not what they seem.

Enter a collection of bizarre crypts that commemorate a kingdom that never was. Learn the terrible secrets of these holes in the earth, and confront what lies yet further beneath. Dance upon the tongue of ancient horror.