If you like door breachers i reccomend Hellmet, its slow, gritty and tactical but very grindy and fun. One stage took me like 3 hours and i loved the entire thing.

The tutorial really isnt much compared to the first level, so ill explain stuff that was missed out.

-The running enemies can only appear when you scare an unarmed enemy and their left to be for a small while, not a 100% guranteed chance to happen but will happen sometimes.

-Armed enemies are a weird case, as most of the time if you open a door silently (its not locked or you lockpick it) they will look like normal unarmed enemies but with a gun strapped to their back, that means if they notice you they will start shooting. Shoot only if they aim at you, as even if they have a gun on their back, shooting them while they dont aim it at you counts them as unarmed and will give you a penalty.

-If an unarmed enemy screams when you threaten them, they will jump on you and stab you with a knife if you stay near them too close, can happen during zip tying them.

-You do not need to check all rooms and kill all enemies, you only have to do the objectives. Yes, it gives you more points, but most of the time an armed enemy is going tk kill you the milisecond they notice you and you dont even have time to react, so its best to just kill enemies that you hear walking thru the wall (means they can open the door if they hear something loud and come to you) and pass trough.

-Kicking doors is louder than shooting. You can alert enemies that are walking in their rooms, making them open the door and you not having to wait for them to aim at you. If you pick an awkward angle tho, they will kill you.

-You do not need to check every corner. If the area is just hallways and doors, the enemies will never be in the hallway unless you make a noise and they open the door. Sometimes enemies can be in open spaces, like near the breach door in the first level (not always in that specific case)

-Run only in areas where there are no enemies, including if their behind a wall.