There is this one Snowflake in the first level. Its a bit tricky to reach but unfortunately necessary for the "Collect all snowflakes in level 1" and the "Collect all snowflakes in the game" Achievement. It took me a fair amount of time to reach the snowflake the first time. But once you get the hang of it, its fairly easy.

The waves are making the platform float up and down. It helps jumping off when it is on the highest point.
Make sure you land back on one of the platforms.
The same jump can be also done from the left platform, mirrored.
Make sure you do not hit the the Fish when jumping.



Here are the steps on how I reached the snowflake:

• Go to the very right edge of the platform until the left side is the closest distance to the snowflake.
  
• The platform doesn't tilt back until you cross the centre of it.
  
• Start running from the yellow line up the ramp.
  
• Jump off the Platform as late as possible, at the green line.
  
• While in the air, at the height of the Snowflake or the red line:
  move the character back to the right and collect the Snowflake.

Hope that helps anyone who struggles getting that Snowflake