Obstacles

There are many obstacles encountered throughout the game. Some need to be destroyed with a specific weapon, while others are unavoidable. They usually function in the same way

Gun

Vent grates: These grates are encountered throughout the game, blocking vents. They are easily destroyed by a few bullets from any weapon, as well as grenades and missiles.

Hatches (gun): Function exactly the same as the vent grates, but they seem to be some sort of trapdoor instead and are slightly larger.

Grenade

Grenade doors: A very thick metal door, almost like a very small bank vault door. Requires two grenades to destroy, the first only caving it in.

Hatches (grenade): The exact same as other hatches, but can only be destroyed by grenades.

Boulders: Boulders that are destroyed with a single grenade. These are not very common.

Grenade pipe: These seem to be some sort of ventilation unit. When a grenade is fired into one, the explosion travels through the pipe and hits an enemy.

Foam

Foam door: A regular door but with some sort of security scanner guarding it, which will detect Jason and block his way with metal bars. The scanner must be shot with foam to progress, and unlike other obstacles, it will stay destroyed.

Fans: A ventilation system of some kind. When shot with foam, the fans stop up and it explodes.

Moving platforms: Many objects like this are encountered throughout the factory, but never elsewhere. They usually move on rails and when they reach one end, they go to the other end with a brief pause in between. When hit with foam, they stop in place, making platforming easier.

Missile

Missile door: Essentially a bigger and stronger grenade door, although with red accents rather than green. It also is like a bank vault door, and even requires two missiles like the grenade door requires two grenades. Does not respawn.

Missile hatch: Just a missile variant of the typical hatch, takes only one missile.

Friction Dampener

Metal crates: These usually are required to be destroyed with the friction dampener to clear the way to wherever you are trying to go with it. The only recurring obstacle that needs to be destroyed by the dampener.

Other

One way trapdoor: Jason can fall through these, but cannot go back up through them. Usually, they lead to a room below a ventilation shaft.

Elevator: By riding inside, on top, or on the bottom of elevators, you can sometimes access different areas, the main example of this being the segment where the missiles are unlocked. Other times, they are just elevators. There is a unique elevator early on in the game which travels up a diagonal slope, but this design is never seen again.

Fan: There are two variants of this, listed together for convenience. One is destroyed with missiles and prevents the player from climbing up, the other pushes the player back horizontally, and needs to be destroyed by running into it with the friction dampener.

Control panels and similar triggers: These all do the same thing and only look different. Commonly seen in the game and are often needed to deactivate something blocking your way or even just operate an elevator. They should be pressed when seen to see what they do because they don't ever activate traps or something.

Water pipes: When shot enough, these raise the water level in the room. Used once to reach the ceiling of a room and most notably to destroy a WSA2 Tarantula. A similar object is a valve used to raise the water level in another room, but this is more of a button than anything. Keep in mind that you need to destroy them in order from the bottom up.

Turrets: There are three different objects like these. One is a machine gun turret that is supposed to be used against a large group of soldiers but is technically optional. Another is a missile turret needed to complete a section in the factory, which can instantly destroy most enemies. The last is the device used to paint targets for the nuclear missile during the final boss fight. It is not exactly a turret but functions similarly. The main similarity between them is that they all function like a third-person shooter when in use and are all required to be used, (In the machine guns case, make it much easier.) Since they are used for "boss fight" segments, they are all quite overpowered, the machine gun shoots as fast (perhaps even faster) then your handheld automatic weapons and instantly kills soldiers, the missile turret also instantly destroys smaller enemies and destroys devastators with a few hits, and the missile targeting device launches what would seem to be ballistic missiles, and can destroy other enemies than the airship instantly.

Many other unique objects appear throughout the game, usually specific destructible objects. These are not listed because they are so rare and there is little to be written even about even the most common obstacles in the game.