Primary Objective[edit]
As you see from the introduction video, your main objective is to find the science log and set the self destruct on Prometheus. The game is provided with a map, which has a highlighted route that you can use. However, it is missing a few steps that would otherwise be helpful.
Upon leaving the SSF Exis, head left (closing the door behind you), and up the elevator. On the second floor, take the left exit to corridor A. Walk to the left, and walk through the door to Corridor C. Take the elevator to the third floor.
On the third floor, enter the farthest room and close the door behind you. Get the id card from the scientist, and the video tape at the top-right corner. Head right, collect the laser and id card.
Return to your ship (or wait until it explodes - you can rescue a survivor in the meantime.) When you learn of the explosion, head to the bridge on the fourth floor and use the radio on the right. Select the middle option to call for help (which dispatches a trader ship to pick you up.)
Once help is on the way, activate self-destruct using the computer to the left, and head to Docking Bay 2. If you approach from Corridor A, you will have to fight three mutants in a row coming from the doors. You may find it easier to zig-zag through Corridor C, Corridor K, then Corridor D, although the route is a bit longer.
If you receive a scene showing a woman in a cyropod, you can now rescue her. See Mary below.
If you receive a scene showing two decapitated mutants and have not reached the docking bay, something important will happen, and you need to deal with that before escaping. See blackout below.
Combat[edit]
When enemies appear, they approach slowly. When they enter melee range, they will slowly depelte your energy. While it is possible to run past some monsters, they take a larger chunk of energy if you do so, and should only be performed when making a final dash to the escape pod when at full health.
The enemies are best handled one at a time, which is trivial in most corridors. Aim at them and shoot - each takes about 8 laser shots before they collapse.
If you run out of ammunition, you can head to the armory. It is located to the right of the second floor entrance, by taking the left door (be sure to close it behind you to avoid a surprise attack.) You can take four lasers here, but can only carry two at a time. There are additional lasers found on the first floor (from Corridor G, head down for corridor H, and take the left-most door in Corridor I), and the plasma laser found in Engineering (From the third-floor elevator, head right to the elevator, down to floor 2, right and down at the first fork, and through the left-most door.)
If you need additional health, you can take one of the single-use first aid boxes at various places, or use the energizer found in the medlab.
Mary[edit]
About 5 minutes into the game, you will see a woman in a cyropod, and learn about the cyro-chamber deactivation. If you want to rescue her to get the best ending, head to the first floor. When you see the red text message about the cyro chamber, you can enter it - it is found directly left of the elevator. Close the door behind you, and kill the mutant in the room. Open the cyro chamber, and Mary will now follow you.
Take the left exit, wait for Mary to arrive, then go up the elevator. The elevator leads to an infested corridor - quickly head left and enter the door. Open the waste disposal door, and Mary will enter. Close the door behind her, and retract your steps to the elevator on the first floor. (It is not feasable to fight your way through corridor F - the mutants respawn infinitely.)
Mary will die if a mutant touches her, or if you take too long to respond to the cyro announcement.
Blackout[edit]
The blackout occurs after approximately 5 minutes after the cyro chamber is deactivated, and between 30 to 60 seconds after the cutscene showing the decapitated mutants. The blackout prevents you from escaping.
To fix the blackout, head to the third floor, go all the way to the right, and take the elevator down to engineering. Enter corridor X, turn south to Corridor Y, and enter the first room (closing the door behind you). Use the console at the top-right corner to restore power.
During the blackout, you can still see enemies as normal. However, you will be chased by a second generation mutant that is immune to your lasers, is about as fast as you are, and damages you much more quickly. To destroy it, you need to lead it to one of five places. The first is the freezer in the kitchen, located near the second docking bay. The second is the oxygen room, located off corridor Q and corridor R, and requires opening a valve within that room. The third is the reactor, located in the engineering section and requires raising the lead shield. The fourth and fifth places are located on the second floor, in Corridor U, near the starting area of the game. You can trap the mutant in the room with the laser field by luring it in the back of the room and quickly activating the laser field. You can also kill the mutant in the room with the TNT crates, by luring the mutant in the middle of the room, placing yourself as close as possible to the door and shooting the TNT crates: the blast will kill the mutant and propel you outside of the room (if you were close enough to the door, otherwise you will die.)
It is possible to use the mutant to your advantage. While it is alive, no other mutants will spawn in the corridors. If you can turn the power back on, evade the mutant while in the power room, and reach the second docking bay, you will not have to fight the two or four final mutants. However, this is difficult, with the mutant trailing you and nibbling at your health.
Ending[edit]
Once you reach the docking bay and escape, you will encounter Annar in the cutscene. The ending will also change based on whether or not you activated self-destruct (if you don't, it is remotely destructed instead), rescued Mary, or retrieved the science log.