More Points
One way to unlock levels in "Super Collapse! 3" is by racking up a lot of points very quickly. While being a good player and looking for chain reactions is one way to do this, you can multiply the points you gain by tapping the space bar to speed up the blocks. Faster blocks equals a higher score. This secret is especially helpful on the early, easy levels.
Coins
The other way to unlock parts of the game is with coins. Different levels in Quest Mode have coins hidden. Look for the light green tree near the store in Fledging Fields or in the middle of the palm tree in Isthmus Oasis. In Aqua Land, click on the light blue starfish near the rock. There is a pack of two coins in Pastoral Fields, which is accessible by clicking on the tallest sunflower in the bottom-right-hand corner of the screen.
Final Level Unlock
To unlock the last level of the game in Quest Mode, you need to get to Blasted Blockade. Then destroy the Grey Blocker in the Bomb Shaker Baby game to get a special coin.