To be honest the banner seems way too large, I'm a web developer by trade and we generally consider 120px to be the optimum height for a banner, with 200 px being the absolute maximum which is generally only used if the nav elements are within the banner.  The reason for this is usability, a banner any larger than that takes up a huge amount of space, particularly on small screens, and forces users to scroll down to actually use the site in any meaningful way. If you really want a huge banner I would suggest a splash page or landing page which then leads to the main site which has a smaller banner. Have you ever heard of the term "above the fold"? it refers to all the content which is viewable without scrolling down, it is the section where you place your most important content, and in an ideal situation, all of your content, it is the area that will get the most impressions and the area which people will most commonly use to navigate your site.

 The title banner is decoration, it is to accentuate the rest of teh page's content, rather than distract from it. Which is why you will notice most large sites have a fairly small banner and tend to stick to fairly neutral colours for the banner.  I would suggest trying out one of the many colour palette generators online and sticking to 3 main colours for the sites layout.

 I would suggest that both your current banner and the new banner both distract from the content of your site and decrease usability, discouraging repeat users and long stays. I do hope this feedback is not to critical, hopefully you can find some constructive points to help you with your design

If you make a gif out of it you need to make it smaller. I have a fast internet connection, but it still takes a few seconds to fully load the banner, which is bad. I can't imagine how long it will be when it's animated. Also, for slower connections than mine it will be terrible. You could say that there is no need to wait for the banner, but as p0ss says, it's the biggest thing one sees and I expected there to be navigation links or something important, so I waited and was deceived :)

But besides that, the idea seems to fit your theme. But if you need so much space, maybe rather use that as a (skippable) intro in the game? Then you have no worries about the size/lenght.

It is a lot better than the previous banner!

It is a bit big but you could negate that by removing the margin at the top and pulling the menu upwards and making it central.  See mockup here:

http://imgur.com/fVp12

Also the background planet is mostly obscured and a bit irrelevant.  Lose it, it'll make the page load faster.