Is it ok................?

[pokemon fan]

Is it ok to miss some shadow pokemon? Will it effect your game.

[Psyducky]

I don't think it will affect your game in major ways. However, you have to catch and the purify the shadow pokemon and one way to get Ho-Oh at the end.

[Jirachi]

I'm not sure if it affects the game.But you can only beat the game if you do catch all the Shadow Pokemon.