SCP Foundation

If you haven't tried R6: Siege yet, you should. It really nails all aspects of the breach-and-enter special forces game design. That being said, I think there's a lot more to the appeal of MTFs than just special forces power fantasy.

I honestly think this would be accomplished best in single player. Adding co-op to a game usually makes it more entertaining, sure, but it also leeches a lot of any tension from the experience. Tension, fear, and uncertainty should be an MTF game's bread and butter, and I wouldn't want to spoil that by playing with my jackass friends, as funny as that sounds.

That also would free up the developer to be able to really nail each anomaly. You could design levels to fit the narrative of any given skip, with a premise in the form of a briefing, followed by escalation, rising action, or discovery as the player moves deeper into the anomaly, followed by a horrifying or tense resolution as the MTF reaches its goal.

Moved to Games and Hobbies.

I think I can try to make a game for ya

I don't know of any MTF Games but you can search for MTF mods that were made in Containment breach. Or an official MTF game set in containment breach I saw a while ago.

I can make one for you… Because Unity's particle system is awesome

The game Deadnauts by Screwfly Studios is a lot like this, though it's a squad-based RTS/Roguelike. (I highly recommend it.)

Basically the idea is that you're the voice on the radio for a group of deep-space salvagers ala Alien or Event Horizon. Each run-through has you exploring a series of randomly generated ships, with a huge variety of procedurally generated enemies and backstories. One run you might be dealing with an alien contagion that turns victims into blind zombies that hunt by scent, another you might be dealing with an infestation of teleporting critters that see in the infrared and can only be killed with sonic weapons.

Needless to say, the cloning bay sees a lot of use on certain runs.

This is exactly what I meant not knowing exactly what anomaly it is and having to tactically adapt to the situation and errors have severe consequences and punishing with slow tactical gameplay that can go to shit real fast, and I'm a nutjob who prefers to have challenging gameplay that demands a lot out of the player.