Undertow is a side scrolling dual-joystick shooter developed and published by Chair Entertainment and released on Xbox Live Arcade. The game was originally released on Xbox Live for 800 Microsoft Points in November 2007.
Undertow was made free for 4 days in early 2008 as a sorry gift from Microsoft.
The game is a dual-joystick shooter set deep under the Atlantic Ocean. Players must fight their way through hordes of underwater enemies and try to capture the opponent's base. The player who captures all the bases wins the game. Another way to defeat the enemy is by eliminating all his respawn points (number of respawn points are indicated above the number of bases left to capture).
The game has both a single player as well as a split-screen/online multiplayer mode. The single player portion of the game consists of three short yet intertwining campaigns, each about five levels in length, in which you play through a few maps trying to take the control points. Multiplayer is a collection of various modes in which the goals are basically congruent to those of the offline campaigns.
Marines - The fastest and most agile of the four classes. Marines' primary weapon has a high rate of fire, but is relatively weak, as is their armor. While they are not the most effective class, they can be formidable once upgraded to level 3, due to their speed and quick weaponry. Recommended for players who are all about speed.
Dragoons - A slightly slower class than Marines, their armor is tougher and weapons stronger. Their guns lack the range of others, but they do pack more of a punch. Dragoons are still considerably fast, and can hold their own well against powerful opponents; once upgraded, they are nearly invincible. Recommended for players who want a bit more speed than strength, while maintaining a good combination of both.
Corsairs - The lightest vehicle class, they are somewhat similar to the Dragoons. Naturally, being vehicles grants Corsairs better armor protection as well as considerable offensive strength. They host a good amount of speed, and their light torpedoes have a particularly good rate of fire. Upgrades grant them better defensiveness and firepower; Corsairs are more on the "strength" side of the Dragoon equation. Recommended for players who prefer combat capabilities over high speed, but like a good mix of everything.
Destroyers - The most powerful class available. Destroyers come in the form of large submersible vessels, and have very strong armor along with powerful explosive weaponry. However, they have the slowest movement speed and rate of fire. This makes accuracy crucial when playing, especially against others online. Despite this, the heavy ordnance offered by this class makes dealing with large groups of enemies while keeping a safe distance somewhat easy; they are practically impervious to attacks when upgraded. Recommended for players when clearing large groups of enemies or assaulting control points.
The class types have their own general varying abilities. While vehicles make use of more powerful weapons, their projectiles are able to be shot down by the smaller characters. They also have less maneuverability overall and cannot fit through some narrow spaces (although these are far from being large hindrances). Regardless of positive and negative aspects, class choice usually comes down to player preference.
Undertow was free to download for all Xbox Live Gold members between January 23 and January 27, 2008. Microsoft chose to give the game away for free to all Gold users as consolation in the light of recent network issues that occurred during holiday 2007 due to an influx of users. This influx made several Xbox Live features crash for several days, keeping some players from playing their games.