how do you get foundation on halo 2?

can anyone tell me how too get foundation on halo 2?  :?

It's been a while since I played, could you refresh my memory on what foundation is?

Foundation is the smallest level in Halo 2, remotely resembles "Wizard" from the first Halo.

Beat the game on any difficulty. On the last level, make sure you perform a
Banshee trick (preferably one you haven't done yet). This should unlock the
multiplayer map Foundation.

Note that Foundation has also been made a download from Xbox Live. No need to
unlock it if you have Live.

Another note: By Banshee trick, I mean a barrel roll or flip. Something special
that the game told you to do with a little pop-up screen while flying around.

Note III: If you don't unlock it, I can't help you much. It's really glitchy. I
have some friends that unlocked it right away after beating the game, and others
who have beat it several times on varying difficulties and performed every
Banshee move known, and still haven't succeeded. Xbox Live is your best bet all
the way around.

Disclaimer: Above info taken from http://db.gamefaqs.com/console/xbox/file/halo_2_secrets.txt

I hate the level itself. It's soo frickin' tiny and annoying and I hate it!

actually, it's not too bad, but i think it would've been better to put more unlockables than just foundation. some of the classic halo guns, maybe?

hey thank you guys ! escially trkorecky thanx!!!!