So I expect you're looking for hints or something. Alright then.

Save your bullets where you can, by using the land mines.
Beware of falling machinery! Remember you can crawl under low ceilings… Press the down button twice to crawl (on flat surfaces)
Plan your route. Keep an eye on how many lift passes you have.
To get past the stomping pillars, lean against them while they're down.
Once you've extended the rope in the Ancient Shrine you can gain access to the spanner you passed earlier.
You need to use the jump boost from the spring to get to the second key two floors below. When you get the key and open the hidden door, do not be tempted to use the jet pack straight away, but go back to the previous level first.
The Herbert Droid needs repairing before you use the remote control. But even if you do that bit wrong, you can still get past it by placing a landmine next to it and stepping on it, which will destroy it.
Don't waste fuel when using the jet-packs, as there's only just enough to get done what you need to do.
When you get the jet pack in the Crews Quarters, you need to go down to the lowest level first and collect the spanner. Then grab the fuel on the way back and go up a level. Don't linger, but grab the lift pass on the high platform, go up another level and you should have just enough time to get the lift pass in the pit there, and get back up again before the fuel runs out. This sequence is perhaps the hardest part of the game.

Enjoy!