I am very surprised and impressed at the level of detail and faithfulness to Demon Slayer! First off, the eyes are the exact same as the anime. Second, the bodies aren't blown out of proportion, and are pretty close to the source material. Third, the mannerisms during dialogue are pretty accurate as well.
My biggest like is the animations; A custom rendered Zeniko 'ultimate'? Custom rendered scenes with accurate locations and poses? The H-Animations are pretty decent as well, but they're a little cut and dry.
The combat system has more dedication than I'd expected, too.
Biggest complaint? Tanjiro (or MC) looks pretty thin, and his clothes don't fit on him quite the same as the others. If I remember correctly, Tanjiro is relatively short with a more muscular build after his training.
The dialogue itself isn't cringe in my opinion, and the pacing isn't just a fantasy wish fulfillment (despite that being what this game is basically). The story isn't very far along at all, but I'm looking forward to future updates!