You can use the Pink Monkey as an alternative character in the mini-game Dance Monkey Dance. You recieve her randomly from the gotcha box. It is not known whether you have to complete certain stages in the game before she appears as she VERY rarely appears and can take four thousand gold coins and up to get. It is, however, a guarantee that you will have most (if not all) of the gotcha box items before she appears.
When playing as Spike, push select to go to the gadget select screen. Then select the monkey net. Push R1 when the net is selected. You should hear a sound. Get out the gadget select screen and then select the monkey net. You now have a water net while on the ground. Fire a net by pushing the right control stick button.
Clear these certain stages to unlock these minigames from the Gotcha Box.
There is a way to get to the end of Castle Frightmare without going through the obstacles you encounter if you take the right path when you first enter the castle. When you first enter the castle you will notice that you cannot use the left path unless you go all around the castle and activate it, but you can jump on top of the railing on the left side and jump over the stone blocking it and activate the switch without going through all the obstacles.