Ummm...
Well, after the last 4 episodes (which I loved) this one comes as a bit of a disappointment. It feels very rough and disjointed. The whole thing feels like a bunch of scenes badly linked together with no plot at all, and some of the humour feels as though you're trying far too hard to be random.
Random humour doesn't work in spades, and for the most part you killed the whole BFM premise with things like Mel Gibson's safari and the steel horse. Some of the drawings have been changed too, such as the motions used for the mouths when talking. They look a lot more basic.
Overrall I laughed at a couple of things, such as Man-Spider in the bath and the "Back With The Boys Again!" thing but thats about it. A big disappointment for BFM. If you're going to make a 6th, watch the first few and see the difference in quality between those and this please.