Tips and Tricks
There are two types of power-ups. The first are random cards that appear on the playfield, ranging from a bomb that eliminates cards within a radius to worm and gopher power-ups that can take out an entire row or column, depending where they're positioned.
The second are more concentrated power-ups, which you'll use whenever they pop up. These include a wild card that pair up with any given card on the playfield (so you can continue your chain), or a Hot Shot power-up, where a gopher will zap cards with his ray gun in one flail swoop.
When you see power-ups, use them when the time feels right. Some can clear away bothersome cards on top, letting you get to better ones on the bottom. The gopher rocket and bomb in particular are quite helpful with this method.