Here is the full list of all 43 Knack 2 trophies - there are 27 bronze, 12 silver, 3 gold and 1 platinum.
Performed your first Knack upgrade.
Acquired all trophies.
Defeated Rothari.
Defeated Gundahar.
Defeated the relic monster that Xander created.
Defeated all Titans.
Defeated the last boss.
Learned the Heavy Punch from Ava.
Learned the Hook Shot from Ava.
Learned the Boomerang from Ava.
Learned the Ultimate Move from Ava.
Defeated 300 enemies using punches.
Defeated 300 enemies using kicks.
Defeated 50 immobilized enemies.
Defeated 100 enemies using Jump Kicks.
Ran 26.2 miles.
Found 30 chests containing relic energy.
Broke the blocks of 50 enemies.
Defeated 50 enemies using parries.
Defeated 500 goblin enemies.
Defeated 700 robot enemies.
Found 10 treasure chests.
Completed your first gadget.
Acquired your first crystal relic.
Unlocked your first Crystal Knack.
Acquired your first gadget part.
Acquired your first Knack medal.
Equipped a combo meter and landed a 100-hit combo.
Stunned enemies 50 times with sunstone bombs.
Cleared a Time Attack stage.
Cleared a Coliseum Attack stage.
Defeated 10 enemies as small Knack.
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.
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.