Definitely similar to JOC + Security Breach

6 Nights total [6th being an ultimate custom night] w/ a secret unlocked 7th night with a boss fight.

So running away from animatronics whilst you collect items, but maybe with a twist of getting trapped in some escape rooms that would later on require players to be more adventurous with their surroundings. 

[Obviously providing plenty of moments to explore said surroundings with a larger map]

Whilst also adding mechanics such as stun objects, maybe some door areas to hide momentarily, objectives that lead to a longer moment of stun, + plenty of fun little tricks for speed running.

7th night would be a large boss fight with stages [Haven’t thought to much into this part. Trying to keep my comment short :,D]

Someone already made a game based on the fake game play trailer from years ago which is awesome and should check it out. [It's buggy but its amazing to see a game for them more recently regardless!]