Meet Amazing Alex - a creative kid who likes to make barmy contraptions out of toys and other things he finds lying about the house. In this physics-puzzler, it's your job to slot in the missing pieces to make his chain reactions come to life.
The fourth chapter is The Treehouse. These 32 stages take place in Alex's backyard getaway, and introduce a few new toys. We get to play with the bouncy ball, the remote control helicopter, and the zip wire.
If you get stuck, load up the level fresh and then recreate the setups shown in our screenshot walkthroughs. If you follow our advice to the letter, you'll beat the stage and unlock three stars on every level.
Level 1 - Angry Bird
Level 2 - Giant Drop
Level 3 - The Evil Dr. Pig
Level 4 - Chopper Pilot
Level 5 - Chopper Rescue
Level 6 - Alarm!
Level 7 - Ball Boy
Level 8 - Bellhop
Level 9 - The Great Escape
Level 10 - Barking Dog
Level 11 - Bellyful of Coins
Level 12 - Ski Lift Sabotage
Level 13 - Pirate's Puzzle
Level 14 - High Jump
Level 15 - Drag & Drop
Level 16 - Skatepark
Level 17 - Alien Escape
Level 18 - Boing!
Level 19 - Quantum of Mayhem
Level 20 - The Dog Returns
Level 21 - Bullseye!
Level 22 - Refueled
Level 23 - Mrs. Doll I Presume
Level 24 - Pinball Machine
Level 25 - Particle Accelerator
Level 26 - The Ride Home
Level 27 - Underworld
Level 28 - Valet Parking
Level 29 - Storm the Castle
Level 30 - Oil Pipes
Level 31 - Safe Landing
Level 32 - Free Them All