Do the following achievements to unlock the corresponding effect:
More Credits: get 3-4 hours of total gameplay time and you will get more credits. At 6 hours of gameplay you should have 9 credits
Gallery #1: complete trial mode and don't use any.
Gallery #2: complete the game using any difficulty and this Gallery will be opened in the Appendix Menu.
Chain Meter: press Z during gameplay to bring it up
Sound Test: complete the game using easy difficulty and don't use any.
Game Mode Option: complete the game using Normal Difficulty and don't use any continues.