An upgraded version of Metal Slug 2, titled Metal Slug X, was released in March 1999 for the Neo Geo MVS. It fixed slowdown problems from the original game, and increased the difficulty. Metal Slug X also introduced some new elements to the game system;Much of the music has been remixed or altered.A new announcerMany stages have the time of day changed. Instead of individual levels being set at either day or night, the stages can take place at dusk, twilight, or sunset.It is now possible for the player character to become fat by collecting food items in every stage after Mission 2; in the original game, the obese transformation was only possible in Mission 4.All levels contain an increased enemy count and new enemy placements, as well as different enemy characters, and new boss placements.Vehicle types and locations are different.There are more power-ups, POWs, and items (particularly food) in each mission. These items are often hidden.Many environmental elements have different reactions when shot, such as exploding with unexpected results or randomly spewing out items or enemies.Stronger versions like the heavy machine gun, flameshot, shotgun, laser rifle, and rocket launcher are available. Each deals more damage than their normal counterpart, has a different appearance and a wider (or longer) area of impact. If the player happens to be fat while using these heavier weapons, they appear differently and can cause even more damage.Several new weapons are included: Stones, Iron Lizard, Enemy Chaser, Super Grenade, Drop Shot, and a new Golden Metal Slug, which is available in Mission 3.Added Fio's death sound (In Metal Slug 2, she uses Eri's)The original art for Metal Slug is shown at the end of the game while the credits are rolling, instead of the black screen used in Metal Slug 2.

Revolution X is an arcade rail shooter game developed and published by Midway in 1994, featuring the rock band Aerosmith. It features gameplay similar to Midway's earlier Terminator 2: Judgment Day. In the game, players battle the oppressive New Order Nation regime and their leader Helga, who have abducted Aerosmith. Players use a mounted gun to control onscreen crosshairs and shoot enemies using compact discs. The members of Aerosmith are hidden throughout the game's international locales and must be found in order to receive the game's true ending.The game was a critical and commercial success, and was ported to various consoles as well as DOS computers. These ports were negatively received and reportedly dissuaded Midway from making a sequel.

South Park: Chef's Luv Shack is a 2D game show-style party video game based on the television show South Park. It was released in 1999 for the Nintendo 64, Dreamcast, PlayStation and Microsoft Windows. Its gameplay involves playing minigames and the ability to play against other players in a challenge for the most points. It also involves trivia questions about South Park and other topics.

Street Fighter EX2 (ストリートファイターEX2) is a 2D head-to-head fighting game with 3D graphics co-produced by Capcom and Arika and originally released in 1998 as a coin-operated arcade game for the Sony ZN-2 hardware. It is the sequel to the original Street Fighter EX, a 3D spin-off of the Street Fighter series. An updated version of the game titled Street Fighter EX2 Plus was released in 1999 in arcades as well and subsequently ported to the PlayStation the same year.