Heavy Metal Slug is a 2.5D fan remake of Metal Slug, created for the Old Games Remaster jam! I put this together in about a week, and it was an interesting experience outside of my usual faire. I managed to get about 80% of what I was shooting for implemented, though I really consider this more of a prototype or demo than a finished game.
You can grab it on itch.io, or take a look at the source on GitHub.