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