Complete the following requirements to unlock new ships.
Ship
How to unlock
Unlockable Ship: Orchid
Complete Stage 5 (any) Using Tigerschwert.
Unlockable Ship: Tigerschwert
Complete Stage 5 (any).
Special stage
First, unlock stage 5E (you don't have to beat it), then turn on easy mode again and enter the level select screen. Despite easy mode normally being limited to A-grade stages, 5E can now be played as well. It's not the same as normal mode's stage 5E, however, but a hidden bonus stage.