Mickey Mouse

In recent discussion with some work colleges from Australia, we struck upon the phrase "It's Mickey Mouse" and it turns out that they use this phrase to mean its good, and we use it to mean is bad.

Has anybody else come across this?

Here in the US the phrase does not mean "good" or "bad".
It is usually an adjectival phrase meaning "insignificant" or "petty" as in:
"There are so many mickey mouse rules and regulations here".

Mickey Mouse
1. (rhyming slang) grouse; wonderful; excellent.
2. childish; unsophisticated; shoddy; cheap.
grouse
1. excellent; wonderful; terrific.
From _The Penguin Book of Australian Slang_ [Originally published as _The Dinkum Dictionary_ in 1988] by Lenie Johansen

Mickey Mouse adj. [1030+] (Aus.) excellent, wonderful, the best. [Mickey Mouse = grouse (Aus./N.Z. sl. 'excellent') ...]
From _Cassell's Rhyming Slang_ by Johnathon Green