Level Design advice.

[The chaser]

Here is my how-to make a good level guide:

-Take a LOT of time with lighting. Lights mark the difference.
-Add the most details as possible.
-If the map is a castle, put things of a castle. The entities and static objects mark the difference.
-Put a LOT of sounds. Our world is filled with them, a CS without sounds isn't a CS that should be downloaded.
-Remember: Billboards are very useful when you add light. Here is a photo of what the billboards can do:

-Don't put unnecessary notes, add messages, ideas from the character. That will add life to a CS.
-Make the player care about what's going on.
-The music. Never forget it. I play the guitar, and, as a musician, I can tell that music adds a LOT of quality. Without going far, the amnesia enemies have each one it's music. Every song "shows" how the enemy is. The grunt is a song that tells you "he is searching you...". The suitor. It has very fast music, because the suitor gives a lot of stress.
-The particles aren't the most necessary thing, but if you can add them, do it.
-Of course, no cheap jumpscares.

So, here finishes my guide. I hope that helps you.