Not hard and will contribute to all the other achievements. There are 3 minigames...of course there are since thats in the description
. Anyways the game modes are Flyswatter
, Thread Needle
and Cardboard Theatre
The following just tells you what the minigames are basically.
For Flyswatter all you do is aim a gun and try and hit as many flies as you can, going for the gold flies will get you another achievement.
For Thread The Needle you controller a rocket...or a needle? and have to go through spinning shapes. If you go through 20 you will get another achievement, its kind of difficult though, was for me anyways.
And finally the last is Cardboard Theatre which is where you just hit rockets and clouds and other cardboard items. If you get your rocket out of the theatre area and go to the left there is a fireplace that will get you yet another achievement.