Trench stages 3, 13, 15

Right at the start, you'll be moving up a bridge towards a locked door. You can shoot the lock off with R + Y, or if you're feeling fancy, just use your knife to cut it. Once inside, there's nothing much to see, so head through the next door with the yellow light. After going down some stairs and through another door, you'll get your first look at the ooze. Don't panic, there's no fighting here yet, just keep moving forward.

Continue down the stairs and take a right. The elevator's out of power, so you'll need to go left and follow the corridor. Keep an eye out in the last locker on the right – it's got a <<Green herb>> for you. Keep going, and some rats will jump out of a power box. Go around the garbage and through the door with the green light above it. Before you enter, check the locker to your left for some <<Handgun Ammo +10>>. Now, head through that door.

You'll find yourself in front of a crate in the center of the room. Interact with it, and a cutscene will play, followed by a save point. You're good to go for now!

This stage is all about careful exploration and managing your resources. You'll likely be dealing with more environmental hazards and tougher enemy placements here. Remember to use your scanner (D-pad up to switch to it) to spot hidden items and enemy weak points. If you're low on health, keep an eye out for those green herbs – they're your best friend.

Pay close attention to your surroundings. Sometimes, the best way forward isn't the most obvious. If you encounter a tough group of enemies, try to lure them into a choke point where you can pick them off more easily. Don't forget about your sub-weapons; they can be incredibly useful for crowd control.

By the time you reach Stage 15, things are usually heating up. Expect more intense combat scenarios and possibly a boss encounter. If you've been keeping up with your ammo and health items, you should be in good shape. If not, now's the time to backtrack slightly if possible or make every shot count.

Remember the dodging mechanic (tilt analog stick forward/backward + B) – it's crucial for avoiding heavy damage, especially from stronger enemies or bosses. Timing is key here! Also, if you get knocked down, mash Y to get back up quickly, but be aware that you're limited to your handgun in that state.