All wild Pokémon and obtainable Pokémon in the demo cannot be Shiny, with the exception of the starter Pokémon Grovyle, Combusken, and Marshtomp during the first adventure. However, since the demo does not these Pokémon appear in their normal coloration except for a red star on their summary screen and a sparkle effect when they enter a battle. After the first adventure, they are no longer treated as Shiny in any way.
No, you cannot get a shiny Glalie. However, you can obtain a shiny starter, but it will not appear as shiny.
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