Gain Ground is an arcade game that was ported to the Sega Master System, Mega Drive/Genesis, and PC Engine (TurboGrafx-16). In 2004, it was re-released in Radica Games' TVPlay Legends Vol. II TV Games compilation. It was remade in the PlayStation 2 title Sega Ages 2500 Series Vol. 9: Gain Ground, which was released only in Japan. The Mega Drive/Genesis version was made available on the European and Australian Virtual Console on February 2, 2007, and was made available in North America on February 5, 2007. The game has also appeared on Sonic's Ultimate Genesis Collection for Xbox 360 and PlayStation 3. The game has also appeared on the Sega Genesis Collection on the PlayStation 2 and the PSP. On June 1st, 2010 the game became available on Steam as part of the 'Sega Mega Drive Classics Pack'.
In Gain Ground, players control one of a set of characters at a time. There are twenty characters, each with different weapons. To beat a level, players must reach the exit point with at least one character or destroy all enemies on the level before time runs out.
Littered across the level are captive characters, which can be rescued by walking over, then escorting the controlled character to the exit point. If a player controlled character is killed, that character turns into a captive, except that they will disappear if the next active player controlled character dies, exits the level without them, or the player has no characters left in their party.
The game is over when all controlled characters in the party are killed without any reaching the exit. However, there are three continues which allow a player to restart the level with their original three characters.
There are 40 levels in the arcade version of the game. The Master System and the Genesis/Mega Drive have 50 levels in the game. The last level can be beaten without the previously stated "suicide tactics".
There are twenty playable characters in Gain Ground, each with their own strengths and weaknesses. Each character has a minor, weak weapon which can be fired in any direction, and a special weapon which has different capabilities from the normal attack and which vary between characters.
The characters in Gain Ground also vary in which hand they hold their weapons. This was originally done purely for cosmetic purposes, but it was very soon discovered that this feature made it easier for some characters to shoot around certain walls and obstacles than others. When selecting a character for a situation, one must consider the character's speed, weapon type and range, and with which hands they hold their weapons.