I really like the art-style but couldn't wrap my head around what works now as a loop and gave up after a couple of minutes. I am sure it is a great game and you did really good on the game play part. But I think a bit more explanation to make it easier accessible would've been great. I also think the explanation screen in the level selection confused me more, than it helped.
Still very well done, especially for your first jam!
Edit: After thinking a couple more minutes about it and looked at the help screen for 5 minutes straight. I got it. Haha.
For anyone else struggeling like I did, here is a hint: Look at the river lines in the help screen around tile with trees and look at how many trees there are on the tile.
Really good one! Now it makes so much more fun!