To defeat the first Boss after World 1 you have to color all of the balls to blue. Do not shoot the balls at the Boss as it does not have any effect.
Extra Life:
When you are in the first level, Artic Antics, at the end is a mammoth up on a cliff. Jump onto the furry rascal and you will get an extra life.
Easy Lives:
To get easy lives, you must have beaten the fourth boss and have the bazooka. Then go to level 1. Around the place are those big elephants, go to the beginning of the level, die, then shoot them again.
Defeat N. Gin:
To defeat N. Gin, shoot at the flashing pads on his robot suit. Four of the pads on the first suit will fall off. The pad underneath his viewing area will not fall off: it will just stop flashing. The two easiest pads to hit are the ones that fire missiles, (the middle is also quite easy too), then his arms are the last two. When he broings up his arm, there will be a few seconds before he starts firing, so this is the best time to shoot at the end of his arms. When you have destroyed all the flashing pads, then he will get into another suit which is even harder.
This time, the flashing pads are four missile launchers, one on the far left, and one on the far right. The last one is just under N. Gin's ugly mug. Hit and destroy all these pads, and you have an apple bazooka.
Get a 3 Second Time Trial on Wizards & Lizards:
First hit the clock at the start of the level to start the time trial. Then press Select. You will warp to the end of the level and then earn your platinum relic.