Here is the full list of all 15 Micetopia achievements worth 1,000 gamerscore. It takes around 1-2 hours to unlock all of the achievements on Xbox One.
Rescue Aunt Rose.
Defeat a bunny.
Defeat the golem boss.
Find five missing pieces of the fountain.
Find three missing pieces of the fountain.
Get the roll skill.
Rescue Ashley.
Defeat the dragon boss.
Get the bow and arrows.
Rescue Uncle Smith.
Get 100 green gems.
Find one missing piece of the fountain.
Get the double jump skill.
Rescue the mouse Kid.
Defeat a goblin.