Timberman Character Glitch
Go to an unlocked character, hover over it, (make sure the locked character is behind or in front of your unlocked character) press right or left and right after press select. You have to do this really fast, it might take you a couple tries.
Locked character select
To select a locked character you need to have an unlocked character that is next to the locked character you want. For example you have Mr. Tree and the next character is Sir Tim and you have him locked. To be able to play with Sir Tim just go back to Mr. Tree and press the select button and the next button at the same time and done. Now you can play with Sir Tim. You can do this with any locked character beside an unlocked character.
Tips and Tricks
Pick a dominant chopping side where you are more comfortable to start your game.
When a branch appears at the top of your screen to the time it hits the top of Timberman's head is 4 chops. So, count to 4 and then switch!
Usual patterns with few branches in your way: chop twice, switch, chop twice, switch.