got the same problem as perfidia... i am stuck because i didn't pick up the yellow key! the problem is that at the point where you have crossed the bridge with the hammer it's impossible to get back but to move on you need the key :/
You can get back through that spot, you just need to hit the block from across the gap, then go around the hammer and hit it again in the same direction. It's possible, but not easy!
 "Seedling"){kind=icon}
You can get back through that spot, you just need to hit the block from across the gap, then go around the hammer and hit it again in the same direction. It's possible, but not easy!