Dixie Ball, a free Civil War adventure game for Linux and Windows:

Lee is trapped somewhere between this world and the next. His corporeal body has disappeared, replaced with a ball sporting the Army of Northern Virginia’s battle flag on its sides.

He needs your help on this journey to the afterlife. Can you guide him from a facsimile of his families homestead, to the mountain summit and help set him free? Do you have what it takes to overcome despair, and puzzle out solutions to the obstacles in his way?

Inspired by Marble Madness:

Christopher played Marble Madness on the Nintendo Entertainment System as a kid. It was a short yet awesome game, full of charm. A few years ago he decided to make a marble adventure game inspired by it. After much research, our team settled on the American Civil War for our indie game's theme.

Free and Open Source:

Our game was made with the Godot Game Engine(version 3.5.2), and is both free and open source. Yes, you heard that right, it's free. No paid DLC, micro-transactions, loot boxes, or other nonsense. All we ask is that if you love the game you’ll tell your friends about it. And maybe leave a positive review on the game page. If you are really feeling generious, consider throwing us a few shekels. Every bit helps.

But why a pro confederate game in current year, isn't that racist?

To answer that, here is a quote from Dixie Ball’s lead developer, Christopher Shilts:

Over 600,000 men died during the American Civil War. The Union soldiers are held in high honor. The hundreds of thousands of men who died fighting for the Confederate States of America have had their names dragged through the mud, and the monuments to their sacrifice destroyed. I believe the men who fought and died in that terrible war should be afforded the same respect for their courage and sacrifice regardless of which side they fought on. This game is my way of honoring those who have been so shamefully wronged.

Haven't given Dixie Ball a try yet?