The basis of Five Nights in Abandonment is kind of a mix of Fnia and FFPS.

The main feel of the game is to look fun and welcoming, but to be creepier and darker the deeper you go down the rabbit hole. Adding a shading of grime and rust along with the disturbing designs.
(Got the inspiration from @DevilRabbitStudios , check them out.)
I still need to think more of this plan and keep it within the plot.

Gameplay(concept):
The game will be switched into 3 parts.
- Testing: Test old animatronics suitable for the restaurant. (Found by Management segment)
- Shifts: Standard night shifts. (Deciding on task nights like FFPS or standard cycle.)
- Management: Parts of the game that allows exploration but still isn't a safe haven.

I can't promise anything, this is all just a concept in my head and hear the feedback from it.