I've always craved something like this too. Of course, you can crank the biter difficulty, but you only get two outcomes: it's too hard and you can never build

I've always craved something like this too. Of course, you can crank the biter difficulty, but you only get two outcomes: it's too hard and you can never build a base that lasts more than an hour, or you manage to arm yourself from the beginning and biters stop being a problem very quickly. I'd really like biters to be a threat I need to pay some attention to for the duration of the game. Evolution isn't really a factor because as you say, once you have laser turrets, you're set. Even red bullets suffice.