I've split it up into sections to which you can jump if you want to:
Make your way off the south end of the screen and then the east. There you will see a conveyer belt carrying buckets of junk up to the screen above. Stand where you will be picked up by one of the buckets [5] and you will be transported up. When dumped onto the horizontal conveyer belt, stand and jump [15] before being shredded.
With Roger's exceptional balancing skill, make your way to the west until you enter a structure with a robot in it. Get into the machine that is hanging from the railing. Don't delay too much in doing this, the robot might get nasty if you hang around for too long. Once in the machine, go left and you'll end up going round onto the back part of the rail. When in the centre of the back section of the rail on the first screen out of the structure, push the button and the grabber will pick up the warp motivator [30]. Go east for a bit, going round the bend at the end and coming back onto the front section of the rail. Push the button to release the grabber at the point where the rail just starts to bend up and the warp motivator will be placed in your ship-to-be [45].
Next, go west again until you return to the structure, stop the machine in the middle of the screen, get off and fall down the chute [50]. You'll end up being dumped into a pile of rubbish in a rather dingy-looking place. Make your way to the west end of the screen, where the wire enters the wall and get the generator [65] then make go to the ladder and climb up. Go north and then east and enter the tube and go east again. Get mugged [50]. Go back west and west and south, go to the south-west corner of the screen and climb down the ladder. Go back and just take the generator again [65]. This time, after climbing up the ladder, take it [75] and make your way north, east and east again. this time, in the middle of the tube, take some wire [80] and go east again.
Make your way to the side of the big head, as far south as you can go without plunging to your death. Enter the eye [85] and you'll get to your ship-to-be. Go round to the right hand side of the ship and drop the ladder [90], climb up and open the hatch [100]. One inside, put the generator in the compartment [105] and use the wire to connect it up [110]. Get into the cockpit and search the seat [120]. Look at your screen. Put on your engines and your radar and then take off. When you stop, go into combat mode, put on your back shield and then fire and blast your way through the side of the freighter [145].
Go back east, then a bit north and west again. Get to the northern end of the screen and east again. The go out the exit in the north east. Zap Elmo's trash and then go out the back door in the east door. Look around, be dismayed, go back inside and back into Elmo's study. Take the keycard on his desk [508] and then get out of this complex, back into the circular tunnel. Go down (or up) until you get to the door on the right with the card slot. Use the keycard and then use the picture to pretend you're Elmo. Head inside [528]. Push the button and go to the middle where the guys are. Zap the jello [737 (riiiight)].
Wait for Elmo's appearance [538]. Kick Elmo's butt in the robot [638] (you don't need to do anything special, just play) and then kick all Elmo's fighters' butts in your ship [738/738]. Make sure you are travelling at attack speed when you fight the skull-fighters. If they come from the back, put your back shields on. If they come from the front, put your front shields on. Simple. Especially due to the fact that they alternate between front and back, starting from the back. Knock out five and the rest will split. Then the Two Guys cause some trouble, being hungry and all. Watch the ending and gloat over all your points.