If you are looking to try the core game without purchasing it first, there are two primary official options:
"Inscryption Free" typically refers to the expansion, a substantial free update that transforms the game's acclaimed first act into an endlessly playable, standalone roguelike experience. Kaycee’s Mod : The "Endless" Update Inscryption Free
You apply "Skulls" to your runs to increase difficulty, similar to heat levels in other roguelikes. If you are looking to try the core
Critics from Eurogamer and Rock Paper Shotgun consistently praise the game as a "wonderful nightmare" and a "beautifully cursed creation". Inscryption Free
A free demo is available on Steam that covers a portion of the initial cabin gameplay.