Okay, a couple of tips of varying degrees of obviousness:
If you're looking for grays, horrors or void eaters then don't kill oozles, biters or grays respectively.
To kill a gray hit it while its tendril is extending (you need to do this three times).
To kill a void eater run up to it and hit it (once is enough) while it's charging its line thingy (surviving till it does this is made an astounding ammount easier if you have the hazard suit).
If you're looking for (razor) queens then get to the end of a small (or any other kind) nest, leave 1 gloopie alive and then don't kill whatever comes until a queen shows up (amalgams screw this up 'cause they're boderline impossible to get off the screen, to get biters off the screen stand near an edge and move out of the way as they lunge at you).
Don't know why I typed all of that out for you, but there it is.
Wow... incredible videos, interesting story (admittedly mediocre gameplay) I love it. It's funny though that the chief complaint is about how no-one is on multiplayer and that would be fixed if more people played.
My only problem with it is there seems to be only one strategy (Build up to the last age, save up to get a super soldier); this makes it a bit tedious (not sure if I spelt that right).
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