Proper way to search?

try changing "resources" to "resource_type"

The API will never look at aliases. Have you tried encoding the apostrophe?

What is the problem? This just works:

http://api.giantbomb.com/search/?api_key=<KEY>&resources=game&format=xml&query=assassin's%20creed

No need to decode or something. However, the api just does not seach through aliasses i believe.