It was a 2d/3d game... best way to describe it. It was like Mortal Kombat 3 with 3d models and a dodge button. The only use of the dodge button was to avoid projectiles.

Two other "cool" features were the ability to use a weapon, and a second grapple attack that most of the time would break a limb. There were also some arena's that had rocks or skulls on the ground that you could pick up and throw at your opponent which did quite a bit of damage and knocked them to the ground.

The last boss an evil God named Shinnok was a weak attempt at a Shang Tsung rip off. Like Shang from previous games you could enter a command to get a certain characters moves. Unfortunately, he didn't morph into that character you would just hear the announcer say Scorpion, Jax...meaning that at that time he would have all of Scorpions moves. Either way as a boss the character sucked and was just way to weak.

Goro was the sub-boss he looked pretty cool in 3d and was kinda hard to kill at times. By way of cheat codes you could also use Goro which was neat.

Speaking of secret characters Noob-Saibot was also in the game as a secret character.

Many of the characters had alternate costumes which was a first in the mk universe.

The fighting system was pretty weak...it was similar to MK3 in that button link combos were used. Unfortunately, almost everyone had the exact same combos. Learn one combo and it will work using any charater...lame.

Anyway, I covered most of it...

Characters in MK4-
Old-
Sub-Zero
Scorpion
Jax
Sonya
Liu Kang
Reptile
Raiden
Johnny Cage
New-
Fujin
Quan Chi
Kai
Reiko
Jarek
Shinnok
Tanya
Boss- Shinnok
Sub Boss- Goro
Hidden-
Noob Saibot
Characters Exclusive to Gold-
Mileena
Kitana
Kung Lao
Cyrax
Baraka
New Hidden Character-
Sektor

The new addition of Kung Lao, Cyrax, Kitana, Mileena, and Baraka was cool. If you had played any previous Mortal Kombat before MK Gold you would notice that those characters do not play any different then they have before.

All of those characters had the same moves and same button sequences to enter to perform them. It was a cool game to get into for about a week, but after you beat the game with everyone I feel that the game looses its interest.