I only played around 100 minutes of Cult of the Lamb, and my impressions is … that is a good game. Cool concept of colony sim + action roguelite, even cooler theme of demonic cult, polished, great visual style, briskly paced. Good game, not great, mind you.
As some have indicated in their reviews, you can notice that is 2 games in 1, and therefore suffer in how deep and good is each part. In special the action dungeon crawler part, the basics of hitting stuff and rolling to avoid are competent, but it really suffers from poor weapon variety (they barely differentiate themselves by being slow but high damaging or quick but low damaging, in addition of one trait like ‘vampiric’ or ‘venom’) and poor perks ("+20% dmg", “+10% critical hits”, etc. I sleep).
I think the reasons some people are loving it (instead of liking it) is fairly simple : it has lots of progression bars! Both explicit and implicit. You level up your followers, you level up yourself with faith, you level up your base and get new buildings, you accumulate more resources, you increase the total amount of followers, etc, etc.