is there an easy way to get the 100 hours achievment???

A friend of mine has told me that he left the game runnin on the cosmos/level select area and this counts.

Or just keep playin this awesome game like i did.

if you do leave it running while you're away you need to have the controller plugged in, i believe.

I can confirm that you can leave your controller off in the princedom and it will count towards the achievement. Easy way is to just leave the game going overnight til you get it (make sure the room is well ventilated).