Yes, I agree there should have been more effects as to when the portal opens and such, but I would rather put more creativity on the game than the trailer. I did the trailer mostly for fun and for other peoples enjoyment. Don't worry I had all those things in my mind for the actual game, so it will be in it with a lot more.
Good, trailers mean jack if the game sucks. Have explosions "snaking" out of the portal.