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 forty levels in the arcade version of the game. The Master System and the Genesis/Mega Drive have an additional ten. The last level has been known for requiring suicide tactics and the wasting of one's character stock, rather than actual skill.
Characters[edit]
There are twenty playable characters, 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.
| Name | Hand | Walking speed | Normal weapon | Range | Special weapon | Range | Note |
|---|---|---|---|---|---|---|---|
| Athra (アスラ Asura) |
Right | Quick | Spear | Short | Arcing spear | Short | All directions |
| Betty (ベティ Beti) |
Ambidextrous | Average | Pistol | Short (left hand) | Grenade | Short | North only (right hand) |
| Cyber (サイバー Saibaa) |
Ambidextrous | Slow | Pistol | Medium (right hand) | Spread missiles | Long | North only (left hand) |
| Fire Knight (ファイアーナイト Faiaanaito) |
Center | Average | Magic missile | Medium | Fireball | Short | North only |
| Gascon (ガスコン Gasucon) |
Right | Quick | Spear | Short | Arcing spear | Short | North only |
| General (ジェネラル Jeneraru) |
Ambidextrous | Slow | Pistol | Medium (right hand) | Flamethrower | Short | All directions (left hand) |
| Glow Knight (グロウナイト Guronaito) |
Center | Average | Magic missile | Medium | Orbiting balls of light | Short | Orbits around character |
| Honey (ハニー Hanii) |
Ambidextrous | Average | Pistol | Medium (left hand) | Grenades | Short | All directions (right hand) |
| Johnny (ジョニー Jonii) |
Right | Quick | Rifle | Medium | Rifle | Medium | North only |
| Kid (キッド Kiddo) |
Left | Average | SMG | Medium | SMG | Medium | East/West simultaneously |
| Kou (コウ Kou) |
Left | Average | SMG | Medium | SMG | Medium | North only |
| Mam (マム Mamu) |
Ambidextrous | Quick | Pistol | Medium (left hand) | Boomerang | Medium | North only (right hand) |
| Mars (マース Maasu) |
Right | Quick | Arrow | Medium | Arcing arrow | Medium | North only |
| Mud Puppy (マッドパピー Maddopapii) |
Ambidextrous | Slow | Pistol | Medium (right hand) | Laser cannon | Long | North only (left hand) |
| Professor (教授 Kyoju) |
Left | Quick | Rifle | Long | Rifle | Long | East/West simultaneously |
| Robby (ロビー Robii) |
Ambidextrous | Slow | Pistol | Medium (right hand) | Surface-to-air missile | Long | All directions (left hand) |
| Valkyrie (バルキリー Barukirii) |
Ambidextrous | Quick | Pistol | Medium (left hand) | Boomerang | Medium | All directions (right hand) |
| Verbal (バーバル Baabaru) |
Right | Quick | Arrow | Medium | Arcing arrow | Medium | All directions |
| Water Knight (ウォーターナイト Wootaanaito) |
Center | Average | Magic missile | Medium | Water spout | Short | All directions (stuns enemies) |
| Zaemon (ザエモン Zaemon) |
Center | Average | Magic missile | Medium | Tornado | Short | Spirals outward, bounces off enemies and walls |