There is no guide for this game yet. But apparently it is EASY POINTS! 

Quick Learner - 10 points

Complete all the lessons in the tutorial.

Beginner’s Luck - 10 points

Get 1 Trophy in Shiverpool area.

Leaving Shiverpool - 20 points

Get 2 Trophies in Shiverpool area.

Welcome to Pen Gu South - 10 points

Get 1 Trophy in Pen-Gu South area.

Leaving Pen Gu South - 20 points

Get 4 Trophies in Pen-Gu South area.

Welcome to the Volcano - 10 points

Get 1 Trophy in Volcano area.

Leaving Volcano - 20 points

Get 2 Trophies in Volcano area.

Welcome to Pen Gu North - 10 points

Get 1 Trophy in Pen-Gu North area.

Leaving Pen Gu North - 20 points

Get 3 Trophies in Pen-Gu North area.

Fashion Freak - 40 points

Unlock every accessory.

Board Collector - 40 points

Unlock all the boards in the game.

Shiny Stuff 1 - 10 points

Collect 25 Surf Idols in surf and leaf slide levels.

Shiny Stuff 2 - 20 points

Collect 50 Surf Idols in surf and leaf slide levels.

Shiny Stuff 3 - 50 points

Collect 100 Surf Idols in surf and leaf slide levels.

Slide Survivor 1 - 10 points

Beat the hi-score and get the shell in leaf slide 1.

Slide Survivor 2 - 10 points

Beat the hi-score and get the shell in leaf slide 2.

Slide Survivor 3 - 10 points

Beat the hi-score and get the shell in leaf slide 3.

First steps - 30 points

Start surfing on the Pen Gu North Legendary wave!

Lucky one - 10 points

Get a total of 4 Shells.

Shell Collector - 20 points

Get a total of 8 Shells.

Shell Lover - 30 points

Get a total of 12 Shells.

Shell Addict - 40 points

Get a total of 16 Shells.

Too Many Shells - 50 points

Get a total of 20 Shells.

Record Man! - 100 points

Get a total of 27 Shells.

The Beach Kid - 50 points

Unlock Arnold by getting the second shell in Shiverpool 2.

Wild Encounter - 100 points

Unlock Elliot by getting the second shell in Volcano 2.

The Geek - 50 points

Unlock Geek by getting the second shell in Pen-Gu South 4.

Figure from the Past - 100 points

Unlock Z by getting the second shell in Pen-Gu North legendary.

King of Boneyards - 100 points

Get 1 Trophy in Boneyards.