Tony Hawk's Underground Cheats (Xbox)

Go to the small building to the left of the cop car. Climb up the wire that is heading
towards the tall building. The tape is in between the gap of the building at the top.

Successfully complete story mode on the beginner difficulty setting to unlock Iron Man.

Get all 129 goals.

Select "Cheat Codes" at the options menu, then enter "letitslide" as a code.
Alternately, get all 129 goals.

Climb the hotel that you start at. Get to the roof and to the right of the pipe on the
right is the side of the building. Grind that ledge onto the wire to get the secret tape.

In the New Jersey level, cross the bridge, then get on top of the large building
immediately afterwards. Shimmy across the tall gate and pull yourself onto a ledge. There
will be a "Tony Hawk 2" icon on the ledge alongside a tall building that will unlock the
School 2 level from Tony Hawk's Pro Skater 2.

Collect six secret tapes to unlock the Bails 2 FMV sequence.

From the large hotel you start at in the Hawaii level, follow the main road all the way
around in either direction. When you find the strip of buildings that are opposite on the
map from the hotel, you will find a large tiki head. Alternately, go out the front doors
of the hotel and through the plaza all the way out the other side. Jump inside the tiki
head's mouth to find a secret area. Skate down the tunnel until the end and boneless into
the air to grab the "Tony Hawk 2" icon to unlock the Venice Beach level from Tony
Hawk's Pro Skater 2. Note: Think of the map as a square. If the beach is at the
bottom, the tiki head is on the top side of the map. It is much easier to get inside the
tiki head's mouth if you dismount your board first.

Start at the entrance of the stadium (where the parked trucks are located, and where you
get into the contest. From there, look at the tape. You should see it above the glass dome
behind the subway-like spline entrance. Go down left from here and wait for a vehicle to
drive out of the tunnel. Skitch it towards where you started from. Make sure you are on
the left side of the car. When you are about to pass the subway entrance spline, get of
the vehicle and spline the entrance from the side. This will launch you across the dome
into the secret tape.

Riding switch is the opposite of what your rider is used to. If you have a regular stance
rider, then switch would be the goofy stance for them, and vice versa. When you do switch
tricks, you get more points than what you would normally get for doing it in regular/goofy
form. For example, doing a Kickflip (regular) results in 100 points, but a Switch Kickflip
gets 120 points. It makes a larger difference on bigger tricks such as specials.

Go under the bridge on the side that allows you to do so. The tape will be floating there
for your taking.

Successfully complete "Slamma Jamma" in story mode to unlock Create-A-Deck mode.