Once unlocked, in the pre-game menu alongside Grunt Birthday Party, I Would Have Been Your Daddy and other classics, you should now find Acrophobia, a modifier that lets players fly around campaign maps when they hold down the jump button.
It’s great for reaching Easter eggs and causing serious mischief – you can finally fly up and hijack those pesky Banshees with ease. Just watch out for your momentum – if you slam into a wall it high speed you’ll risk turning John-117 into Flood food.
Acrophobia isn’t unlocked by default however, you’ll have to kill 343 flying enemies in Halo 3’s campaign on Normal difficulty or higher.
Want a tip for that? There’s an easy spot that I used to unlock the skull in the Campaign map The Storm. Press on until you get to the second outdoors area and head inside until you come across a room with a rocket launcher. A dropship will spawn and send tons of bugs flying into the room. Simply pelt them with rockets and swap to your Battle Rifle to mop them up, then blow yourself up with a grenade to rinse and repeat.
As pointed out by Eurogamer, the new skull can also be enabled for the first two Halo games, meaning three times the opportunities to mess with what Bungie wanted you to see back in the day.
The skull has incredible potential for mayhem, and players are just digging into its possibilities. If you’re hopping in to relive the magic from 2007, it’s definitely worth checking out. If you’re still on the fence about picking up the port, check out the first 19 minutes from Halo 3’s Campaign on PC.
Jordan Oloman is a freelance writer for IGN. Follow him on Twitter.