One of the more aesthetic version differences between Diamond and Pearl, and the third game in the series Platinum, can be seen here. In Platinum snow covers the top of the trees.
But one of the most notable version differences is that while the Starter Pokémon is given out in a different area in Diamond and Pearl, you receive your Starter Pokémon in this area in Platinum.
If the player chose Turtwig
If the player chose Chimchar
If the player chose Piplup