Professor Zombie!

Professor Zombie!
Unscramble the words before the Zombie eats the professor’s brain!
The Professor has left his brain out, and now zombies want to eat it! The only way you can stop the zombies is by unscrambling the words.
The play is simple: press two letters to swap their places.
The action is frantic: can you make the correct moves before the time runs out?
You get 40 seconds on each level to unscramble the words. Be sure to read the clues, as they will help you figure out the puzzle.
Any time left over from the last level is applied to the next. The faster you work on the earlier levels, the better chance you have when things get more complicated.