Play Metal Slug: 1st Mission emulator game online in the highest quality available. Metal Slug: 1st Mission is a Neo-Geo Pocket game that you can enjoy on Play Emulator. This NGP game is the US English version that works in all modern web browsers without downloading. Metal Slug: 1st Mission is part of the Arcade Games, Action Games, and Shooting Games you can play here. PlayEmulator has many online retro games available including related games like Metal Slug 7, Metal Slug X, and Metal Slug X.