Infinite Lives
If you never want to worry about getting a game over and want to try as much as you want, you can input a code at the title screen to get unlimited lives. When the screen pops up, input "Left", "Right", "Left", "Right", "Right", "Right", "Up", "Down" and "B." You will hear a distinct noise that will give you infinite lives.
Slow Down Gameplay
If the action is getting too hectic and you can't keep up, it is possible to slow down the game action. At the main menu screen -- which is different from the title screen -- input "B", "A", "B", "A", "Y", "X", "X", "Y", "R" and "L." This will make everything run in slow motion, including you.
Temporary Invincibility
While Spyro is performing a headbash, he is completely invulnerable against all attacks. This is a useful technique to know against enemies who would have otherwise unblockable or unavoidable attacks, such as projectiles or far-reaching shockwaves.
Jurassic Jungle Puzzle
The Jurassic Jungle Puzzle is one of the trickiest spots in the game, but if you know the proper order for doing this puzzle, it's one of the quickest. When you enter the room with the monkey statue holding the dragonfly and all the other monkey statues, use your flame to hit the gems in the following order: red, green, blue, purple and yellow. This will release the dragonfly.