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.
Cleared one chapter on the Very Hard difficulty level.
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.
Defeated the last boss.
Cleared all chapters on the Hard difficulty level or higher.
Defeated all Titans.
Learned all basic power-up skills.
Defeated 700 robot enemies.
Learned all super moves.
Learned the Ultimate Move from Ava.
Acquired your first Knack medal.
Equipped a combo meter and landed a 100-hit combo.
Unlocked your first Crystal Knack.
Acquired all gadgets.
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.
Ran 26.2 miles.
Defeated 500 goblin enemies.
Defeated 10 enemies as small Knack.
Defeated 100 enemies using Jump Kicks.
Defeated 300 enemies using kicks.
Learned the Hook Shot from Ava.
Defeated 300 enemies using punches.
Found 30 chests containing relic energy.
Stunned enemies 50 times with sunstone bombs.
Defeated 50 enemies using parries.
Learned the Heavy Punch from Ava.
Found 10 treasure chests.
Acquired your first crystal relic.
Completed your first gadget.
Performed your first Knack upgrade.
Acquired your first gadget part.