I took the liberty and copied this from the Steam forum. It is a pity that the devs don't post here themselves but maybe this helps answering most of the questions people might have about the game.

The Mansion EA - Q&A

Why Early Access?
Even though the game isn't completely finished, we thought it could be a lot of fun at this stage, and the feedback from players will help us finish it to better meet the expectations of horror fans.

Approximately how long will this game be in Early Access?
The game will remain in Early Access until the complete three chapters are finished, which we estimate to be not less than 8 months. It could take longer as we want to improve the game to players satisfying quality.

How is the full version planned to differ from the Early Access version?
We are currently giving you the middle of the planned three chapters. It's functional, but still not finally polished. In the beginning, we plan to finish all cutscenes in this chapter, add some functionalities, and make changes according to players' suggestions. Then we plan to continue work and add two more chapters with an introduction and two alternative endings.

What is the current state of the Early Access version?
We are now presenting the middle one of three planned chapters. It's not quite ready yet, but it's playable and it's possible to finish the storyline. We hope it will give you some fun already in this form. In the coming weeks, we will try to finish it and give it a complete form.

The game is a horror story presented from a first-person perspective. The player can walk and explore the environment, interact and manipulate objects to move forward, cheat or fight NPCs, but it's not an action game.

Now we have fully implemented:

- 18 detailed rooms and halls of The Mansion to explore, connected with some secret passages
- The graveyard and a lakeshore garden outside The Mansion
- 6 NPSs to deal with
- 6 cutscenes to admire or be scared of
- around 20 more or less complicated puzzles to solve
- 2+ hours of gameplay to solve them all

Will the game be priced differently during and after Early Access?
The current price covers 1/3 of the game. We plan to increase the price by a factor of two when the beginning chapter is added and by a factor of three when the whole three the planned chapters are closed.

How are you planning on involving the Community in your development process?
We will carefully read the game Steam forum, and we will consider every player's voice. We'll do our best to improve the game and take interesting ideas into consideration while modifying the scenario.

We are counting on your help and valuable suggestions in this matter.