SCP-2521-● ● | ●●●●● | ● ● ● ●
SCP-002 the "living" Room
To start off with scp-2521, a fan favorite/popular SCP that could be shown by cutscene or heard through audio log of a test subject saying it's name and dissapearing. It can also just be the SCP-papers laying around somewhere but i think the SCP fanbase/community would really enjoy the actual (first) footage of the SCP.
Not only would this SCP create hype for the game but many people unaware of you developing the game could end up seeing the cutscene anywhere (Instagram, YouTube, SCP-related pages). This could bring you more attention and supporters.
Secondly is SCP-002.
SCP-002 could be actually entered in game by the player and killed off after seeing the horrific "room" Of flesh and human skin/materials furniture.
I thought this SCP would be quite 'easily' to develop/make and would make for some interesting in game interactions.
Last suggestion for SCP is SCP-2427-3
SCP-2427-3 Isn't that well known and that would be certainly refreshing for many people. From the depictions i've seen so far it seems like a terrifying thing to stumble upon.
This SCP is perfect for a horror/thrilling game. Imagine just hearing it coming around the corner and seeing that monster.
It doesn't even necessarily need to be breached during the game, although it would make it much more intense and enjoyable.
There could be various game mechanics to avoid this SCP, one in particular would be luring it into its containment chamber or somewhere else using meat/dead goats.
Outrunning this SCP would be unlikely but it could also be a possibility i suppose.
It states on the SCP wiki that any person that meets this SCP will have a desire to have their purity judged. This could also be used in-game for gameplay purposes.
I suggest to read about this SCP, it isn't very long so it might be really worth it!
There is a bunch of possibilities with this SCP, of course it can also just be used for cut scenes or notes yet do i think this SCP is fitting for this game.
Any other notes:
SCP-2427-3 is depicted very well by Lord Bung in his confinement series on YouTube. The video with this following SCP is linked below.
The SCP is shown around this timestamp: 4:30