A content expansion for Metal Gear Online, the Gene Expansion is the first in a series of planned content packs that will augment the basic game included with MGS4. The pack includes new maps, characters, and options; people who buy the pack will be able to set up games or play in games that have these features enabled, whereas people who don't will not.

The first thing that Gene adds is new maps. These are Coppertown Conflict, Virtuous Vista, and Tomb of Tubes. Coppertown Conflict is a remake of Brown Town from MGS3's online mode. It is a dust-swept town, with sandstorms blowing back and forth obscuring vision. There is an open street for snipers to duel on, and in addition there are tunnels and buildings for more close-range combat. As a whole, the map has a very neat atmosphere; it feels similar to the map Midtown Maelstrom, in that they're both about urban combat with lots of places to snipe or hide.

Virtuous Vista is a long, open map taken from the South America section of the game's single player mode. There's a lot of greenery and tall grass in this level, which means that people who wear green have a good advantage for hiding (in much the same way that people who wear tan or brown on sandy levels have an advantage). The map is pretty much built for long-range sniper battles, with lots of little areas for long-range shooting. The main point of the map is the power station - in team games, one team starts at the power station and the other team spawns at the other end of the map and must attack it. There are also some emplaced weapons around the map - the power station is defended by heavy machine gun turrets, and there is a mortar pointed at the power station that can be used by the attacking team. Both types of emplaced weapons can be used to great effect if teamwork is used; they're both powerful weapons, but they're also both out in the open, which means that a sniper can simply pick off the user if they're not covered by their allies.

Tomb of Tubes is an entirely indoor level - a sewer facility with channels of water going through it. The level is poorly lit, and there's a lot of background noise due to the rushing water. It's a claustrophic level perfect for close-quarters combat, and it's also one of the levels that's dark enough to warrant use of the flashlight gun attachment. The level has a lot of water, as mentioned; it's the only place (that I know of) where water is deep enough to swim in, and it's frequently possible to drown by either being knocked out while in the water, or "playing dead" for too long while in the water.

With Gene, the ability to create female characters has been added. This requires you to make a new character, either by buying a new character slot or deleting your old character (unless you have the Gene pack when you make your first character), and it's somewhat odd that female characters weren't included from the very beginning. The female character faces, like their male counterparts, cover a variety of ethnicities - Caucasian, African, Asian, and Hispanic. The voices have a wide range of personalities, and tend to sound reasonably professional (and they can be customized further with pitch changes). The models for the characters are reasonably proportioned - no giant breasts or skimpy clothing, though they're not entirely devoid of curves. All in all, the female characters seem to be tastefully done.

Another new feature is the inclusion of unique characters - in this pack, those characters are Meryl Silverburgh and Johnny / "Akiba". When the option for unique characters is set in a game, each character is assigned to either the red or blue team. A random person on each team gets to be that team's unique character for a round; after the round ends, another person gets the chance to play as the unique character.

Meryl is a leader gifted with several abilities. She has her unique Long-Barrel Desert Eagle, a powerful scoped handgun, that only she can select as a weapon. Her presence as a leader restores Psyche to all allies around her, and she can wake up a knocked-out character with a single tap (whereas normally it takes a few seconds of holding down the button to revive someone). She also excels at using handguns and conveys a lot of information through SOP - namely, enemies that are targeting her and enemies that she has damaged are both highlighted with SOP.

Johnny's abilities mostly come from his lack of nanomachines. He cannot connect to allies with SOP (though he can still communicate with radio and chat), but at the same time he is immune to enemy abilities that rely on SOP, like Narc and Monomania, as well as items that use SOP like the SOP DESTAB (in Base mode) or the Scanning Plug. On the other hand, there are some disadvantages brought about by his lack of nanomachines; committing friendly fire causes Johnny to curl up and apologize profusely for a few seconds, instead of the normal "SOP Locked" status that prevents you from firing your weapon for the same amount of time. Furthermore, his famous character trait - his irritable bowels - comes into play after he kills 3 or so enemies, and he has to pause to use the bathroom. Afterwards, a stink cloud surrounds him, causing anyone caught in it to choke and cough. Johnny's special ability is that he can see every trap on the entire map, and he's also capable of disarming traps from a safe distance. Johnny has two special weapons - the "regular" special weapon, the XM8 Compact, or his "advanced" special weapon, a large-caliber automatic sniper rifle. The latter can only be purchased in Drebin Points mode for 10000 Drebin Points.

The final additions in Gene are Survival Mode and the Rewards Shop. Survival Mode is a mode that takes place for four hours (8-12 Central Time) on Fridays, Saturdays, and Sundays. Players form teams of 6 people and see how long they can survive against other teams in randomly determined games. Beating a lot of teams in a row without losing gets you more points; the points are then used in the Reward Shop (which, at the time of writing, is still not up) to buy new clothes, gear, camouflage patterns, and face paint. Survival is an interesting mode that allows a team of friends to get together and really put their teamwork into practice, and it's definitely a fun mode despite how rarely it's playable.

As a whole, the Gene expansion's main problem is how it's been handled by Konami. It seems that they were wholly overwhelmed by the response that the pack got and underestimated how many people would want to play it. There are only two servers for Survival mode, the MGO Online Shop was down until recently because too many people were on trying to buy the expansion, and the Rewards Shop is still down because they can't deal with the number of people that would try to get in. However, the expansion itself and the content it provides definitely adds to the MGO experience, so this is a must-have for any fan of the game. The price for the pack is 12 dollars; for 15 dollars, you can get "GENE+", which includes a character slot (at half regular price).

The MGO Gene Expansion gets an 8/10.