NeoRAGE is the first publicly freely available NEO-GEO emulator. You can load with it games such as Metal Slug or many others SNK or Capcom games.

Metal Slug 1 is the first part of an scrolling shooter video game for the Neo-Geo console/arcade platform created by SNK. (...)

Metal Slug 2 is the second part of an scrolling shooter video game for the Neo-Geo console/arcade platform created by SNK. (...)

Metal Slug 3 is the third part freom series of scrolling shooter video games for the Neo-Geo console/arcade platform created by SNK. (...)

Metal Slug 4 is the fourth part freom series of scrolling shooter video games for the Neo-Geo console/arcade platform created by SNK. (...)

Pteroglider is a fun and innovative incarnation of the classic arcade space-shooter genre.  (...)