Keep a notepad right next to you, and record every single thing the aliens say!
Ah, one more tip because this is just pretty frustrating, and will waste some brain power if you don’t know.
There is an alien race which will give you a series of number in binary. I spent a long time analyzing the numbers and trying to fit them into a contextual way they mean something. They are actually an old telephone number, I believe to the studios head quarters. They have no meaning in game, don’t waste your time trying to figure out what they mean. In the Sega Genesis version, they were changed to clues to hidden items on planets. I don’t want to spoil anything, but I have a feeling we’re all adults w/ limited spare time, no need to waste brain power on a “puzzle” which has no relevancy to the in game stuff.