I've split it up into sections to which you can jump if you want to:
When you've come out of the closet, walk left and you'll enter the library. If while walking around you get told that you hear footsteps, quickly go through a door or go off the edge of the screen because if you don't you'll be caught and shot. Go out through the door to the left and left down the corridor to find the dead crew member. Search him and take his keycard [1]. Go back to the library... an old man should stumble in through the right hand door and fall to the floor. Look at the man and he should talk to you, telling you that people are stealing the Star Generator and says the name that the information cartridge is stored under [3]. Go to the cartridge retrieval unit and enter the code for that particular cartridge. Take the cartridge [8], but don't try to insert it in the computer or you'll be killed.
Now you have to escape the Arcada before it explodes. Go left and then down the elevator then right. Have a look in the Star Generator room on the way (the broken door) and take the magnetic widget thingy on the pedestal in the middle of the room [9]. Take the down elevator, then head to the right. Look at the console in front of the shuttle bay window and press the open button [11]. Go right and put the keycard in the slot [13] and you'll enter the elevator.
Open the white closet and get the space suit [15]. Click on the button on the orange storage thingy to get the gadget that's there [17]. Leave through the airlock to the right and enter the pod. Wear your seat belt. Look at the console above your head and push the power button (the rightmost button). Pull the throttle [32] and you'll launch, escaping the Arcada. Press the autonav button [34] (the leftmost button on the console above your head) and the system will find a planet on which to land.
Carry on around the path until you reach the end... walk towards the sign on the far spike [48] and you'll be transported underground. Get the top of the stalagmite that has been glued on then go to the left. Throw the bit of pink plant at the grate to stick the grate monster [53]. Go past the grate and off the left. Put the piece of stalagmite on the geyser [57] to open the door and leave through the left of the cave. Put the glass in the beam [62] and take the path up the back.
In the next cave, dodge the drops coming from the ceiling [65] and carry on to the right. (If the drops are dropping too quickly to dodge them, save your game and put your game speed on maximum and just try to run blindly through them... you should make it eventually.) Make sure your dialect translator (gadget) is switched on before walking right again. You'll be told to kill Orat and returned to the surface.
Make your way to the right until you find the cave entrance inside the big skull; enter it. Throw the dehydrated water at Orat [70] and pick up the piece of him that's remaining [72]. Make your way back up to the top of the ridge and back to the alien's chamber. When told to, drop the Orat part and walk forward.
The people will give you a skimmer, but first put the cartridge into the console at the back of the room. Read the data [77] and write down the destruct code for the star generator. Take the cartridge and enter the skimmer [87]. Dodge the rocks and you're on your way to Ulence Flats [112]. (You don't lose points for skipping the arcade sequence so you don't have to do it if you don't want to.)
Now we need some more money, so go to the slot machine. Use the widget on the slot machine [127] and it'll affect it so that you always win. Play until you break the bank (you'll have over B$300). Go left to Tiny's Used Spacecraft. Don't buy the ships on that screen; go to the back and buy the only ship on the screen behind [131]. As Tiny said, you'll need a droid to fly the ship so go right to Droids B Us. Give your other coupon to the salesbug. Give your buckazoids to the salesbug when the nativation droid appears and you'll go out to fetch it [135]. Head back to the ship that you bought. Enter the ship and you'll take off [160]. Tell the droid to head for the sector that you heard in the bar (you'll have to use the navigation codes in the documentation) and soon you'll be in view of the Deltaur.
Push the chest so that it's underneath the grate then use your Xenon army knife to open the grate. Enter the grate [156] and crawl to the left. Climb the ladder and then into the tunnel to the right. Kick the grate at the end and you'll end up in the laundry room [164].
Open the washing machine and enter it [169] then exit when you've been washed up. Now you're in a Sarien uniform; pick up the Sarien ID that's on the floor near your foot [171]. Leave the laundry and enter the left elevator and head left when you get out. Take the elevator to the upper level and head right until you reach the armoury. Show your ID to the droid and when he goes to get your gun, steal a grenade from the counter [172]. The droid will give you your gun [173] then head left. Drop the grenade on the guard [178].Head back to the lift on the left. When you get to that screen you'll trip and lose your helmet. After losing your helmet you'll be attacked if caught, so if you see a guard shoot him [181]. Be sure to encounter and shoot at least one guard for the points.
Go the the Star Generator room. Search the body and you'll find a remote control [184]. Use the remote on the Star Generator [187] to deactivate the shield around the Generator. Look at the console and enter the destruct code [197]. Head back to the lift, enter it and then enter the right hand lift [198]. Enter the shuttle [201/201] and you've escaped. Congratulations! The Deltaur explodes and you save everyone!