Dude Its a GameStop exclusive code...So yes you can enter your code with a silver membership. This is b/c code entry for products/gold memberships are possible. The real question is why anyone would have a internet connection and not have xbox live. Also pretty sure if not connected online to xbox server(silver) means no download content available in game.
the grunt birthday party skull makesit when you get a headshot on a grunt the grunt yells "yay" and explodes with confetti
If you are trying to find the Grunt Birthday Day party skull, but when you get to the place and it's not there, you may need to get a headshot on the enemy grunt. You should then found the skull in the middle of Crowsnest, which is the second level.
This skull is a silver skull. It is strictly for your entertainment and you won't get an achievement for it.
it pretty much makes the aliens mad and they try harder to kill you. like the grunt that tries to kill you whe you get the skull.
skull fossil: Cranidos Armour: Sheildon
I'm not sure what fossils you're looking for, but you can get Helix ,Dome,Amber,Armour and Skull Fossils. In Diamond, you can get a Skull Fossil. In Pearl you can get a Armour Fossil. All other fossils can be gotten after both games.
play on normal or higher. start from the start of the mission and go to the location
Skulls modify certain aspects of the campaign, often increasing difficulty. For instance, the Blind skull completely eliminates your HUD and the Mythic skull increases your enemies' health. Some are amusing, such as Grunt Birthday Party, which causes confetti to launch into the air from a Grunt that receives a headshot.
If you are trying to find a Grunt B-Day party skull but when you get to the place where you wanted to buy it, its not there, you should use your phone to look up other stores in the area that might carry it. You can then give them a call to see if it is in stock before you drive there.
Armour,Skull,Helix,Dome,Old Amber and Root Fossils.
Red Skull is a human being, enhanced its true but his body is still made out of proteins and limestone. Iron man has steel armour. If Red Skull hits Iron man he fractures his fist. If Iron Man hits Red SKull - the skull comes off.
Its not an achievement, its a silver skull. On the mission "Crows Nest" (the part where the bugs are coming from the pipes after you drop down and Cortona talks to you, at the end at the edge), you will notice that you can go underneath the walkway you were just on. The skull is at the back of that passage.