Players choose from several soldiers and push through 2D side-scrolling stages, shooting enemies, throwing grenades, and rescuing prisoners. The game features branching paths, so different route choices can lead to different enemies, vehicles, and bosses. Players can mount tanks, submarines, jets, and other Slugs to increase firepower. Losing a life requires continuing with credits, and infection can transform a character into a zombie with altered attacks and movement, changing the tactical flow.

Marco Rossi

A balanced soldier with reliable standard firepower.

Tarma Roving

An all-around unit suited to handling a wide range of weapons and vehicles.

Eri Kasamoto

Fast and agile, ideal for careful movement and quick reactions.

Fio Germi

A core series character with a balance of offense and survivability.

Rescue prisoners whenever it is safe, since they often reward powerful weapons and score bonuses. Try to keep strong weapons for bosses instead of spending them on minor enemies. On a first playthrough, take the more straightforward route to learn stage layouts. Vehicles are powerful, but be ready to eject before they explode. Take damage only when necessary and learn boss tells to reduce losses.

In many arcade versions, continuing lets you keep progressing; some builds also include extra mode options or post-clear content, but conditions vary by release.

Tips and tricks

Watch for hidden items in destructible scenery.

Tips and tricks

Do not overextend while rescuing prisoners in dense bullet patterns.

Tips and tricks

Learning each boss's startup animations greatly improves survival.

User Reviews

Packed with variety, so repeated runs still feel fresh.

User Reviews

Excellent pacing, weapon feel, and presentation make it a benchmark arcade shooter.

User Reviews

Branch routes and vehicle variety are often cited as reasons it is considered a series peak.