Easy Money
Watch the credits until they end, then wait until they finish again to get 50 Coins.

New Items
Change the system date to a different time or date in order to get new items in the shop. This works well for going back to a date that you missed, or forward to a date that you cannot wait for (for example, Christmas).

Shantae Background
Touch the Ping Pals logo exactly at midnight (00:00:00) when the chime sounds to unlock Shantae's sexy background in the "Backgrounds" section of the Items Shop. Note: Try setting the system clock fifteen seconds before midnight to give you enough time to prepare to do this.

Bonus Items
Enter the Items Shop on various holidays (Christmas, The Fourth Of July, Halloween) or your birthday to find new items.

High-Lo Mini-game
Always pick "7". The game usually chooses a high number, and the worst you can lose is 5 Coins if it selects "1".