Boktai: The Sun Is in Your Hand Cheats (GBA)

Dark Gun Pieces

Dark Lens: Complete the game once 

Phantom Frame: Complete the game twice 

Chaos Battery: On Hard difficulty complete the game once 

Information Room

Complete the game once and save it. Start a new game and on the saved file of the
completed game you will come upon a Solar Tree which will have a wap next to the little
hill going up to the raised area. To be teleported to a small room with five Hint Blocks
which has information about your game data you have to access the warp.

Pink Solar Tree

Gather at least 1,500 Sols to get the Pink Solar Tree. 

Astro Battery: As the evening turns to night look at the Pink Solar Tree. 

Chaos Battery: Obtain the Pink Solar Tree and complete the game on Hard mode.