Huge fan of SCP Foundation. So much great content. There appears to be SCP Entity for every monster concept. Recently discovered SCP-5391 and SCP-5514. Considering incorporating it into our ExORION Survivor: Alien Invasion | Kaiju Survival Terror to grab a piece of the established SCP fan base.
In regards to “BM: Entanglement” don’t know if you can use Half-life’s “Black Mesa” in the title without some heat from Valve. There are plenty of SCP Site Facilities locations to use. Could probably play on the words SCP: The Black Lab. Which in itself could be also be reference to SCP-023 Black Labrador Retriever (Black Shuck) with anomalous Powers. You could also play on the obsession with The Number 23.
Had to review more about SCP SL and watch some youtubes to get some understanding of your concept. I can appreciate the various Roles players can choose (as we’re doing similar in ExORION). The roles should have their own strengths and weakness, which I can be presented in the form of Skills.
I personally like the small inventory. If up to me, it would be even smaller, comparable to Left4Dead’s HUD. I would also use a singular inventory system to manage it all: Stats, Weapons, Tools, Skills, Anomalous Powers, etc. For more in-depth health, I can easily visualize Survival Statistics being applicable, but I would also try to keep the number of stats small.
Left4Dead had Team Game Mechanics and Animations to support Team Play. I would include Team Rewards. Team game play can be implemented in many ways, one of the easiest is providing Friendly Fire Options. I would be more in favor for the options to cooperate always exists for use, instead of forced and mandated.
Would keep all of the Roles, but definitely extend on the number of them, especially SCPs. I would add the Role of SCP Entities who assist the Foundation like SCP-073, SCP-999, others. The Game should have its own never-before-seen SCPs that only exists within the Game itself. There are so many great SCPs to add, and Translating the various SCP Anomalous Abilities into Mechanics will be fun to develop.
Ultimately SCP XXXX The Black Lab itself could be an Anomalous Place/Area/Dimension similar to SCP-167, SCP-823, SCP-3008, SCP-1678, others.