There's exactly eight Beat them Up games on the Neo Geo: Sengoku 1, 2, 3, Ninja Combat, Burning Fight, Robo Army, Eight Man, and Mutation Nation. Very popular with players, will Mutation Nation beat the famous Undercover Cops of Irem? We shall see that. It's possible to play two simultaneously in Mutation Nation, and three in Undercover Cops. Irem's M92, built around two NEC processors and the same ultimate Yamaha chip as MVS, is the favorite system of the firm to develop its arcade games since 1991. Significantly less powerful than the Neo Geo, it benefits a slightly higher resolution (320x240 against 320x224) but displays much less colors; its processors and architecture don't allow it to perform titles like Blazing Star or Mark of the Wolves, but back in 1992 it's still a powerful system, that can compete without problem with its rival.

The pictures of Undercover Cops speak for themselves: the M92 is able to provide gorgeous graphics. In addition,  Irem's designers have an undeniable talent, with the high level of qualityseen here. The style is easily recognizable: look at games like In the Hunt, Gunforce, Major Title or later, Metal Slug (yes, Nazca are the same guys). The draw is beautiful, the colors well chosen and the backgrounds feature great reliefs. Too bad, however, that the stages are not all as beautiful as the first one, which is by far the most successful of the game. Mutation Nation, with a different style, also offers beautifully crafted screens: with futuristic-apocalyptic tendencies, the designs are exotic, varied, colorful, and don't lack nuances. However, it's obvious they don't pack the same "dramatic" intensity than those of its competitor, whose "end of times" side is much more palpable! More interesting, more elaborated, the Irem game's graphics are a cut above those of Mutation Nation, despite the capabilities of the Neo Geo.

Mutation Nation    88                        95   Undercover Cops

Here, our two opponents are almost even. The sets are quite lively and feature fast scrolling stages and animated elements in the landscapes (sea, sewage, elevators, and other doodads). As for the protagonists, there is a little more speed in Mutation Nation while Undercover is a bit more decomposed. The enemies are more varied and better animated in Mutation Nation, while UC proposes  a wider range of moves for the main characters. Anyway, they're a little stiffer, and also slower than in its competitor. Some slowdowns can be seen in the game of Irem, especially when playing with friends (the game can sometimes be quite messy!) while Mutation Nation, simpler and not taking the risk of putting too many enemies and as much details as Undercover Cops on the screen, creates a somewhat sharper result and never slows down. So here's a slight advantage for the game of SNK.

Mutation Nation    89                        88   Undercover Cops

For Undercover Cops, musics are like the graphics: the best is in the beginning! While the theme of the first level is taking and rhythmic, the melodies eventually become fairly common in the next stages. The sound effects are good quality, while being simple and packing rather few - but well chosen - vocals. Mut'Nat, in a electro-punk register is definitely more powerful and has more personality. The music is varied, catchy and well adapted to the action. They're accompanied with sound effects honouring its support! 'Powerful' at will for blows, with engine noises, fire, screams... One more point for Mutation Nation here, using greatly the power of YM2610.

Mutation Nation    86                        78   Undercover Cops

Forty minutes to clear SNK's game (in normal mode), with six stages long enough, punctuated with many Bosses and sub-Bosses. Five levels are present in Irem's game, a little shorter, lasting about thirty minutes total. In both the strenght might clearly be the cooperative play, but Undercover Cops catches up with its three simultaneous players and three different characters, against two in Mutation Nation.

Mutation Nation    72                        74   Undercover Cops

In Mutation Nation, there is no weapon to pick up, nor destructible elements throughout the game. Punch opponent with the A button, and bashing the button within the right timing performs combos. Maintaining low or high, or just no direction, while comboing, executes different ones. B jumps, and allows some juggle hits if you catch the good timing. Press A+B simultaneously makes a 'Dragon Punch'. One throw per character is available, a knee hit or a headbutt: it's few! By keeping the button depressed you will, according to the color chip collected, launch a devastating attack: five different exist. Undercover Cops has what is lacking in Mutation Nation: poles, vehicles, barrels, bricks, bats... your route is littered with elements to swing in the face of your opponents! There are also plenty of destructible things. The player chose between three fighters packing a more elaborated range of moves than Mutation Nation (dash, special attacks, running attacks, throws). The jumped attacks are also a little more accurate than in its rival. However, the behavior of enemies is linear and the game can sometimes feel repetitive. Mutation Nation does a little better at this, with more flexibility and less elusive enemies. Anyway, it must still confess far exceeded in this area by Irem's soft, which is more comprehensive and attractive.

Mutation Nation    80                        90   Undercover Cops

Mutation Nation loses by a few points this duel with Undercover Cops. The title of Irem won the match with a more complete and enjoyable gameplay and also smarter graphics. Overall, Mut'Nat realization is high and pays the luxury to outperform its competitor on the soundtrack and animation. But that's not enough! If the title of SNK is doing well technically, it would have been better by providing an array of moves a little wider, weapons, and elements to destroy in the stages. All this is very well thought out in UC, which is filled with fun and surprising things. It remains in the history of Beat them Up as a major title, and despite this defeat, Mutation Nation figured as a great rival in this versus.