Nice
Short and sweet. Easy and very intuitive.
I guess I'll put a small walkthrough here.
Replace the rock with the pocket knife.
Use the knife to cut the hair of the lion.
Grab the hook next to the lock.
Combine the hook and hair.
Drag the mouse cage over.
Let the mouse sniff the keychain.
Throw the mouse at the circus tent.
Open the door with the key and you're done!
See intuitive or at least I thought it was.