There is no official campaign length, and pre-launch numbers from us would be guesses — so here is the structure instead, which the demo makes concrete. The loop is the expedition: take a contract aboard the Tempestad, sail in, haul treasure, get out. Demo expeditions run roughly twenty minutes to three-quarters of an hour depending on tier, greed and how loudly things go wrong — a Basic haul is a coffee-length run, a deep push with a full crew is not. Treat those as demo-era estimates; we time real distributions at launch.
The Story line
Story contracts thread the expeditions together: they uncover forts that expand the map, and eventually open the descent that ends at the Mound itself — capped by The Moundachievement. Between Story beats you'll run ordinary contracts for coin, gear and rank, so "beating the story" is a many-evenings arc rather than a weekend sprint.
What 100% asks
The 27 achievements sketch the completionist budget honestly: reach rank 30, unlock the full playable roster (Seven Willing Souls), commission all nine sacred figures, collect all 13 logbooks and the creature codex, survive five expeditions in a row without dying, and revive fifty teammates. The revive and collection counters alone tell you this is designed as a long-haul co-op habit, not a checklist weekend.
Length questions
How long is The Mound: Omen of Cthulhu?
It's run-based: expeditions last roughly 20–45 minutes in the demo depending on contract tier, and the Story line threads many expeditions together to reach the Mound. There's no fixed campaign length — we'll publish measured run distributions at launch.
How long is the demo?
The demo covers the opening slice — the prologue and early contracts. Most players see what it's selling in one to two hours, and it's free, so the real answer is: until you're convinced.
How long does 100% take?
No honest pre-launch number exists, but the achievement list implies a long haul: rank 30, all characters, all 9 saint figures, all 13 logbooks, 50 revives and a 5-expedition no-death streak. It's built as an ongoing co-op game, not a weekend platinum.