Here is the full list of all 12 Trine 2 achievements worth 200 gamerscore. It takes around 6-8 hours to unlock all of the achievements on Xbox 360.
Feed carnivorous plants with three or more different kinds of treats
Shatter three frozen enemies within one second
Kill an enemy with a thrown hammer bouncing at least once before kill
Shoot 3 arrows in the air and catch them all with the Knight's shield
Complete a whole level playing one character only
Stand on a plank floating on a single airflow for four seconds
Get at least 10 enemies killed by other enemies' actions in a single level
Stand on a conjured box bouncing on any bouncy surface for 10 seconds
Make a bubble sink for three seconds
Construct a tower made of eight objects and stand on top of it
Make goblins die of three different environmental hazards in a single level
Using grapple, swing around an object and reattach grapple again without touching any surface