The player aka The Marine has just arrived on board the UESC Marathon. The first terminal he arrives at tells him that the Marathon is under attack and he then receives a message from Leela directing him to a nearby jump pad that is located through a series of engineering access hallways.
From the last terminal the player is teleported to the next level, Bigger Guns Nearby.
The goal of this level is to survive and make it to the last terminal. Because of the weak Pfhor on this level, this is a good level to practice the running punch techinque, as well as circling packs of aliens to get them to fight each other.
In the room with the Pattern Buffer there is a door that seems to be inaccessible to the player. However, the Switch out in the hallway will open the column that separates the player from the door. The player can also run and jump around the column to the ledge that has the door.
To clear the bottom right room of the projectile Pfhor, either wait up at the openings and use your gun to take them out, or jump down and run circle around them to get them to fight each other.
There is a secret room in the bottom rightmost room on the map. Make sure you approach the room from the right side (you need to open a door to enter the room). Then, with the door open, take a step or three back to get a running start, then immediately as you get into the room, break into a 180 degree turn to the left and land on the small ledge in the middle of the room. One tap of the action key later will get you a clip of each type of ammo. You can also jump across to the small ledge on the other side of the room, follow it around, and make a small jump back to the right ledge and then on to the secret room.
This first terminal is encountered at the beginning of the level, along with an ambush for unwary players. It contains a broadcast sent to all terminals announcing the attack by the Pfhor on the Marathon. It also contains a second a message directly to the player from the AI Leela with a map directing him to reach the teleportation terminal in the hangar bay control room to exit the level.
Hangar Area-5 Engineering Access 50-h<291.7.577.456>
This terminal is found being accessed by a S'pht Compiler and an examination of the contents suggests that it was trying to document aspects of humanity and presumably send them back to the Pfhor ship, but the process was interrupted when the player killed it.
Hangar Area-5 Engineering Access 49-h<294.2.577.456>
This terminal is also being accessed by a S'pht Compiler, and circumstances are the same but there is no comprehensible information here, story wise. (Some of the garbled letters and numbers can be converted from hexadecimal into ASCII characters to yield the word "rocket!")
Hangar Area 5 Teleporter Pad Terminal<220.127.116.11>
In this terminal, Leela describes the invasion of the Marathon as "uncoordinated", but warns that the attack on the computer systems is anything but. She recommends the player kills any Pfhor he finds, particularly the S'pht Compilers, before teleporting him out.
The music for this level is titled Landing, which gives off an eerie atmosphere.
Marathon - Level 0: Arrival