I like to play the last of the Neanderthals, and roll a good Kaumo who will avoid all human contact whenever possible. I start in spring, as in a winter start the cold will almost certainly kill you - usually from starvation rather than directly, as you have to keep setting fire to fallen trunks and so can't stray far from the fire to hunt or fish. In summer and autumn, you can live from berries etc., so I find spring is the sweet spot for the challenge.
I use the "custom - too easy" to roll my skills, as I will need good fishing and spear skill to have a hope of surviving more than a couple of weeks.
I reroll the world until there's a reasonable size island off the far north eastern coast, then get a start as close to that as possible. Normally I won't get closer than a three or four day hike from it. On spawning I discard everything I have except any fur clothing, just enough to stop me dying of cold as I head for the island.
On arrival, I begin the first game course to build my stats a little. I'm starving by now, so the pike it gives early is very welcome. It doesn't last long, though. I hunt and fish, and try to get through the game course whenever I am nourished. To complete the game course you need to visit a human village, which I do. I trade what skins or cords I have for what food they have, and am usually starving again by the time I make it back to my island. The building part of the game course is painful - with just stone tools, it takes a couple of weeks just to make one wall section.
I don't allow myself to trade for anything other than food, and I don't murder anyone.
The watercourse part of the game course gives a handaxe, which I don't use until I give it to the companion you need to finish the course. I allow myself to plant maybe 20 of the seeds the agriculture part of the course gives me, mostly hemp, flax, or whatever else I might be able to make yarn from, as nettles are scarce in the far north east.
I use the BAC mod, so as spring turns to summer the mission is to make a metal knife. It's an enormous amount of work, but must be done.
The biggest difficulty of this scenario is the stone knife - an elk that with a metal knife might net 250 cuts of meat or more, with a stone knife will get you 50 or 60 at most. Of course, restricting myself from trade and it being summer means there is no point in having more cuts, as with only stone tools there is no way I can build a cabin for smoking by this point.
So, I mine ore and cry as I try to chop firewood for charcoal with a rough stone axe. Trust me, it's more torturing myself than gaming. But that feeling if I survive long enough to make the first metal knife... man, that feels good. And it gets even better when I manage to forge my first axe. Love it

EDIT: Around day 115 I managed to produce a rough small knife, and on day 140 I made a rough handaxe. Food has been a real struggle, but I noticed lavarets spawning, and making an inferior lippo landed me 64 of them over a couple of weeks. I produced a decent broad knife and handaxe by day 180, and winter has arrived so soon I hope animals will be wandering across the ice to my island. Things should start getting easier now