Complete the game with exactly zero dollars to unlock the bad ending.
Bonus Stage
When your score has a 7 as the 10-thousands digit(for example 170,000), call Launchpad to take you back home; he will drop you off at a secret bonus stage.
Extra Hit Point
At the right extreme of the second floor, there is a large coffin which is marked "R-I-P". Cane jump on top of that coffin and you can walk through the right wall, which happens to be an illusionary wall. On the other side of this wall there is a chest, which contains the extra hit point.
Get past the talking statue without paying
In the Amazon level, when you will eventually get to a big gray statue that will offer you a way up if you pay a certain amount of money. Choose ''No'' and then make Scrooge turn around and walk a little to his left. You should see one of the enemies that throw plungers at you approaching. Place yourself right under the rope that is at the top of the screen. Now, dodge the plumbers that the enemy throws at you, and then use Scrooge's cane to jump off the top of that enemy in order to reach the rope without paying the statue.
Hidden Ending
Score at least $10,000,000 and then beat the game. You'll see a slightly different ending.
Refill Your Energy
If you have 3,000,000 in your total, you can refill your energy anytime by pressing Select. Each time you press Select, you will consume that amount.
Second Extra Hit Point
For the second Hit Point, move right across the level, until you reach the first pit. Jump down this pit and keep falling until you reach the bottom floor. Just move left until you reach Bubba. To save Bubba just hit the block underneath him with your cane and cane jump from the block to above the ice, which intraps him. He shows you a treasure chest, which contains the second extra hit point in the game.
Bad ending...