Here is the full list of all 8 Lumber King achievements.
You got the skill "Psychic Of Lumber King".
You did a million damage with one shot.
You cleared 20-5 and now it's all sands.
The first time you hit a tree.
For you failed to kill that tree.
You unlocked "Angel Lee".
Said the Iron Folk Tony.
You fed the developer with all DLCs in your storage. Now all your damage will be doubled.