Dawn of Man is a colony sim set during the prehistoric era. Starting from humble hunter-gatherers, you will soon get to conquer agriculture, cattles, copper, iron, and a bunch of other stuff.
The game has a ton of good ideas. That premise isn't just for show; the gameplay does radically change over time as you unlock new technologies. Early on, hunting is your saint grail; it gives you food you can store through winter, skins you can use to make clothes and buildings, bones for tools, ect ect and I uh never really saw the point of doing gathering tbh. As soon as you unlock agriculture however, you get to produce right in your home an absurd amount of food that allows you to increase the size of your colony drastically. With agriculture comes domestication, goats and cows and pigs and a bunch of cool shit that makes it that not only you will never have to hunt again, but you can also get milk and wool and soo much cool stuff. Later again you can unlock metal tools, at which point you'll have to actually work on your colony's defenses, because raiders will frequently invade you.
However, much as I'm hyping it up, the game is slow. It takes a looong time to unlock new techs. Most of the time you'll be waiting for your little dudes to just live their lives until you can unlock the next game mechanic and get to add stuff to your colony. It's perfect if you're rping online and waiting for your partner to send you their reply, but it can get boring after a while.
Another important thing is that the game is clearly... unpolished. I don't mean the graphics (even tho it's clearly poorly optimized considering it came out four years ago at the time I'm writing this and my brand-new laptop wheezes like crazy running it) but I mean there are many, many quality of life changes that coud easily be made and just... haven't. One exemple is the aforementioned techs. You only get a vague description of what each techs are until you properly unlock it. Meaning maybe you got skin tanning, got all excited to the prospect... until you realized that you can't tan shit because you need composite tools, another tech, first. So instead of having a new game mechanic to play with, you're left with even more idle time waiting to once more be able to unlock what you actually need to get this whole thing going (did I mention that unlocking tech is fucking long? Because it's fucking long. I cannot emphasize enough how long this bitch is.) Another exemple would be the in-game encyclopedia to explain mechanics and such. It sucks. It sucks so bad. "Dog domestication allows you to have dogs" ok yes thank you but do I need to like, do something? Do I need to grab dogs? Do they just show up? I had to google up that one. Either don't include the encyclopedia or make it actually good. There are TONS of exemples like this. They're not big things, they can be solved by either a wiki or a mod, but the modding community is nearly nonexistent for this game so you'll just stew in yoru frustration when you inevitably encounter a problem that could easily be solved by a button that is just not there.
The game has a tutorial (which is pretty good) and a campaign, which is also good, if terribly short (three maps.) You have the option to download community challenges, but again these basically don't exist. Out of twenty-ish options on the steam page, I found maybe three I actually wanted to play, one of which turned unplayable. There's the sandbox mode I guess, but since techs are very limited regarding the order you unlock them in & the environments don't change that much, all my playthroughs end up following the exact same pattern. Can be fun for some, but I get tired eventually.
Overall, it's not a bad game. It's a solid 6/10. If it's on sale and you're really craving an easy colony sim, go for it. Otherwise though don't bother, you'll live without it.
Edit: I have now realized that there is no custom mode. There's a creative mode that is all easy peasy, but that's. It. I can't choose what seed I throw in the map generator. I can't pick the difficulty myself. I can't choose the proportion of each ressource. So Dawn of Man is officially three (3) whole campaigns, the creative mode, and then whatever the community made, which is not much. Oh my god this game is so empty it hurts.