Metal Slug — Advance

There is a specific card titled (Card #004) that changes the fundamental gameplay.

There are 100 cards in total. You find them by shooting hidden background elements or rescuing specific hostages.

In Mission 3, you can find it by shooting the corner of a specific block in the first secret cave area. Metal Slug Advance

When active, your character (Walter or Tyra) will die in a single hit .

This mode makes the game play more like the original arcade titles, where players do not have a health bar. There is a specific card titled (Card #004)

Unlike other games in the series, Metal Slug Advance features a card collection mechanic that serves as the main progression hook.

You must finish a mission without dying after collecting a card to keep it. The "Paper Thin" Card In Mission 3, you can find it by

While some are just for display, many cards grant gameplay bonuses like increased weapon power, new "Slug" modifications (like the Slug Gunner ), and access to hidden map routes.