Thanks so much for trying it out! As happens often with jam games, this one turned out a bit harder than I intended.
When playing with a single player, the best method is to dart into the woods briefly in search of the Grim Roots, but return to the cabin frequently to make sure there's no mischief. You don't have the luxury of wandering around in the woods for an extended length of time.
When playing with two players, you can send one player exploring while the other player does guard duty and clears and tills the soil. My favorite way to play is actually to both characters myself. :)
As for the length of the day, I struggled with this a lot. I settled for a short day (20 seconds day and 20 seconds night) because you need a certain number of days to grow your crops, but there isn't all that much you have to do each day. The spiders only spawn at night, but they often arrive at the cabin during the day.