Here is the full list of all 43 Knack 2 trophies - there are 27 bronze, 12 silver, 3 gold and 1 platinum.
Acquired all trophies.
Acquired 70 Knack medals.
Acquired 50 Knack medals.
Learned all super moves.
Learned all basic power-up skills.
Unlocked your first Crystal Knack.
Equipped a combo meter and landed a 100-hit combo.
Achieved 5 stars in every Coliseum Attack.
Cleared a Coliseum Attack stage.
Achieved 5 stars in every Time Attack.
Cleared a Time Attack stage.
Cleared all chapters on the Easy difficulty level or higher.
Cleared all chapters on the Normal difficulty level or higher.
Cleared all chapters on the Hard difficulty level or higher.
Defeated the last boss.
Acquired all gadgets.
Defeated all Titans.
Defeated 700 robot enemies.
Learned the Ultimate Move from Ava.
Defeated 50 immobilized enemies.
Defeated the relic monster that Xander created.
Defeated Gundahar.
Broke the blocks of 50 enemies.
Learned the Boomerang from Ava.
Defeated Rothari.
Defeated 500 goblin enemies.
Ran 26.2 miles.
Defeated 300 enemies using kicks.
Defeated 10 enemies as small Knack.
Stunned enemies 50 times with sunstone bombs.
Defeated 100 enemies using Jump Kicks.
Learned the Hook Shot from Ava.
Defeated 50 enemies using parries.
Found 30 chests containing relic energy.
Defeated 300 enemies using punches.
Found 10 treasure chests.
Acquired your first crystal relic.
Acquired your first Knack medal.
Learned the Heavy Punch from Ava.
Completed your first gadget.
Cleared one chapter on the Very Hard difficulty level.
Performed your first Knack upgrade.
Acquired your first gadget part.