Just to clear this up, "Edge of the Night Sky" (よぞらのはて) is not a minigame in itself. The PokeWalker consists of courses which you can choose when you bring your Pokemon over from either HG or SS. You start off the game with two default courses. Each different course have a different variety of Pokemon that can appear, though we are not sure what exactly at this point. Anything past the initial two courses are unlocked by using the PokeWalker. Edge of the Night Sky is a course that can only be unlocked with Jirachi. These are the only courses that are known about to date:
- Refreshing Field - さわやかのはら (Default Course)
- Noisy Forest - ざわざわもり (Default Course)
- Rugged Path - ごつごつみち (Seems to be unlockable at around 1,000 steps)
- Edge of the Night Sky - よぞらのはて (Unlockable by bringing Jirachi to HG/SS)
To get Pokemon to appear inside of these courses you need to use the different items available to you (the minigames) These minigames consist of the Item Finder (to find items) and the PokeRadar (to find Pokemon) Pokemon that are fought inside of the PokeWalker can be caught and sent back to HG/SS respectively though we do not know any of the specific details as of yet. To use the Item Finder and PokeRadar you are required to use your Watts, which you gain through walking. It is unclear as to how many Watts are needed to use either item as of yet.