Very late to this thread, but just wanted to pop in and let folks know that I picked up Blacklight and absolutely love it.
Here's a mini-review:
I'd been poking around for a game to run an SCP-style game of Mobile Task Force members (mix of military and scientists) investigating a few "anomalies" and possibly some portals to adjacent "realities" like The Backrooms and such. I didn't have a coherent story in my head yet, just some set pieces in a rogue military laboratory using a device to access The Backrooms themselves, and a short list of what SCP creatures I planned to use.
For game systems I'd considered Cortex (my favorite system), but I didn't have a clear enough picture of the themes involved and how the characters would affect them/be affected by them, which is pretty much what you need for Cortex to sing. I'm not a big Delta Green or percentile system fan, and while I wanted there to be a focus on tactical action stuff at points, I didn't want that to be the only thing, so both sides of that took out a few other options that otherwise would've been strong contenders: Savage Worlds is too action-heavy for my tastes, Gumshoe is too action-lite. I'm not a Fate person; anything Fate I would rather just use Cortex. I've been a huge fan of Death In Space, CY_Borg, and Vast Grimm, so I was considering hacking those together.
Then I found Blacklight.
Not only does it have everything I wanted, it has some really neat stuff I hadn't considered, too. The classes and gear are all the highlights you could ever need. Leveraging Shadowdark monsters for various cryptid-like monsters works like a charm, especially if one has Unnatural Selection, an expansion for Shadowdark with a host of new monsters. But even better, there's a great list of "alternate realities" that are simply reskinned concepts like The Backrooms, but they are very thematically reframed, allowing you to bring a lot of other settings to bear as alternate realities in the game world. The reframing does a lot of great work that parallels various SCP origins, so that ties everything together very nicely. On top of that, the class abilities -- which I already mentioned liking -- are extraordinarily diverse and well-written, allowing for that perfect mix of combat and investigative abilities across the spectrum. Non-military characters won't feel completely out of their element in a fight, and likewise the tactical characters will still have fun stuff to do during investigations.
I'll be using Blacklight for this campaign now without a doubt, and without any house rules of note, which is an extreme rarity for me as a constant system tinkerer and game designer. I've already backed
@Scrying Dutchman 's
Modern Necessities so I can have more gear and ideas to bring to bear for the game. It's perfect for what I wanted, and I can't recommend it enough.