When making your avatar
Make it in the likeness of something you think is kool
And stick to this for as long as possible
You actually play better using your own custom avatars

Also don't bother buying all those vancy pantsy upgrades
I made it through the game with level 1 everything (on normal)
But you can upgrade if you want
But I suggest you get your health and energy up high
It really helps on rescue missions
Kill'em all is easy lol

So in the words of infected ( the manual)
So don't touch it... STOP TOUCHING IT!