Demo gives you 20days ingame per map so you can play over and over but for a max of 20 days, which is plenty of time to do stuff. Ive racked up 18hrs on the demo so far. A number of environments are available each with different terrains, food sources, enemies. Start with normal as its easier IMO.
The games tutorial is pretty shit but the concept isnt very hard. You need wood and stone and food which are readily available. From there, you want to build a carpentry, masonry, hospital and renewable wood and food. You need to keep your people happy by building personal rooms and decorations and not working them too hard. Add a market (to get a caravan to come trade), tavern & tavern rooms (to attract heroes which are needed to clear dungeons). There are a number of other things you need but they tend to require better materials like iron which can be very difficult to find. Just finished demo length and didnt find any but still managed to have a sufficient town. I dont build walls or roofs, dont think its necessary and requires a lot of material. You will only attract more people or heroes if your villagers are happy so get a simple setup done then let them chill to increase happiness. Be careful not to lose villagers @ the start of the game cause with only 11 of them initially, if you lose 2 or 3 your productivity will suffer immensely.
Best game i managed was 30 villagers, 5 heroes and was part way thru exploring the 2nd dungeon (this isnt my game below, just a random image).
This was on sale until recently, a lot of people were pissed that it wasn't explained that it was an alpha version though, which doesn't run on a lot of people's machines. Last I checked, the quality also appeared rubbish (the devs couldn't even implement half decent pathfinding or animating their static sprites between tile positions), and nothing happened every time that I clicked the install demo button on steam...
I find newly released demos often dont install with steam - normally just need to wait a few hours or a day and they magically work. The awesomenauts free weekend thats on, when i click "here" to install or whatever it does nothing. Tried it yesterday and today, nothing.
Ended the 20 days with 28 villagers all in woodern armour or better, 5 heroes, had a record 3 caravan visits, 10 deaths in total (many to yetis early in the game), 6 different auto food productions (barely enough to provide enough food), found iron approx day 17, no coal at all made food options difficult and had begun exploring dungeon 2.
Surprisingly, i couldnt get any bread to cook so was stuck with limited meat and mainly fruit/mushrooms.
I had a friend who was always pissed that steam wasn't working correctly. When I pointed out he was playing a pirated steam game that had some cracked steam stuff it would screw up his real steam unless he reset it. After that his steam worked without a problem..