Congrats on making the game for the jam!
You have an interesting and fun concept going on here, I really like it! The biggest issue for me though was the balancing - I always felt I had way too much of one material and then get slaughtered hunting down my last piece of wood to upgrade my equipment.
I think if you ironed out the difficulty spikes a little, this would be top notch and a very addictive browser game experience. That said, we did only have a small time frame to get our games done and submitted, so things like balancing and playtesting sometimes suffer more than we would like :(
I did have fun playing though - so thanks for making it and sharing!