To refill health, complete a block, then select the "Change Monster" option to choose the same monster you finished the block with.
To destroy buildings instantly, take a gasoline truck and throw it at a building.
To play as the following characters, complete the indicated tasks:
Bubba the Blob: unlock the other 23 bonus monsters
Eyegore the Alien: complete the game with the "All Challenges Met" award for all cities
Philbert the Ungulate: complete the game with the "Par Scores Met" award for all cities
Use the indicated monsters to destroy the blocks in the city while the following Bonus monsters are unlocked:
Jack: Las Vegas, 2nd block: play as Harry
Kingston: Las Vegas, 2nd block: play as Lizzie
Leon: Las Vegas, 2nd block: play as George
Marco: San Francisco, 5th or 6th block: play as George
Natalie: San Francisco, 3rd block: play as Gilman
Shelby: San Francisco, 3rd block: play as Lizzie
Edwin: London, 2nd block: play as Wally
Icky: London, 2nd block: play as Leon
Kyle: London, 3rd block: play as George
Amanda: Los Angeles, 2nd block: play as Lizzie
Bart: Los Angeles, 2nd or 5th block: play as Kingston
Cal: Los Angeles, 2nd block: play as George
Harry: Chicago, 2nd block: play as Marco
Nick: Chicago, 2nd block: play as Harry
Rojo: Chicago, 2nd block: play as George
Crock: Hong Kong, 3rd block: play as George
Jill: Hong Kong, 3rd block: play as Amanda
Venus: Hong Kong, 3rd block: play as Leon
Joe: New York, 3rd block: play as Natalie
Rocky: New York, 3rd block: play as George
Wally: New York, 3rd block: play as Kyle
The following items will help you to unlock the indicated effects:
Bananas: Good for George
Chili Peppers: Good for Nick
Fire: Good for Nick
Poison: Good for Kingston
Steak: Hurts Rojo
Water: Venus can drink water from pipe leaks. Gilman is immune to water leaks.