Arti has ported "Mini Metal Slug", a "Metal Slug" remake, to AmigaOS3. It's a one-man-army comic-style shoot'em up game, and it demands some serious processing power: 68040 CPU, fast emulator, or Vampire accelerator is required.

You can find it on AmiNet:
http://aminet.net/search?query=minislug

Arti's homepage is:
https://artishq.wordpress.com

The AmigaOS3 version is based on HunoPPC's AmigaOS4 port of the game. HunoPPC has done a lot of other ports, mostly for AmigaOS4, and some for AROS, MorphOS, Linux, MacOS, Windows.

Titles include "World of padman", "Return to Castle Wolfenstein", "OpenBor"
"Xgalaga", "Aliens versus Predator 2000", "Enemy Territory: Legacy", among others.

You can find a list of his projects on his homepage:
http://hunoppc.amiga-projects.net/

Here's a video of "Mini Metal Slug" running on a Vampire accelerated Amiga:

Sources:
http://www.apollo-core.com/knowledge.php?b=3&note=6140
http://aminet.net/package/game/actio/MiniSlug
https://artishq.wordpress.com/