Hoggle Boggle (protecting 9 Gork cages in Goblin City) was tough but I got it eventually. It is not the only thing needed for "The Cleaner" however. The rest of the achievements needed for unlocking The Cleaner will be available in the Workshop Campaign.

Thanks for the response. These forum topics are all slightly nebulous, it's difficult to figure out which one is the appropriate one to look in/post in.

what workshop compaign??

impossible , that's my 10th time trying everything

the wizards are destroying everything in 1 single fire blast !

new tips please ...

i am using barricades living wall wall blades and spikes

i once reached to the end and this epic cleric healing herself and entering the area of the 9 gorks :(

hope for a better way or a video

thanks

Here's a video walkthrough of Goblin City, using the strategy that I used to get the Hoggle Boggle achievement. This particular video got 3 stars but didn't protect all the rear gorks, because my hands can't move as fast when I have an HDMI cable hanging off the side of the iPad, but if you try this strategy a few times, you should have no problems.
http://youtu.be/jkfbuS6aNQ8