If Metro Exodus was set entirely on the train, it might look something like Keep It Alive (opens in new tab): a game of powering through the post-apocalypse in a train carriage. As a train driver, well, more of a shoveller and a security guard, you have attend to multiple spinning plates, as the train advances from station to station in the world.
First, there's the engine, which you have to constantly fill with precious coal. If you don't—by moving to the right side of the screen and hitting left and right, alternately—a zombie-style creature will begin to climb onto the train. When this happens, you have to jump to the middle of the train, and put a bullet in it. Both coal and bullets are limited, and only refreshed between stages.
When you're not keeping the train fed, and zombies at bay, you need to keep a beating heart—your cargo—alive, by frequently turning a handle. It's a tense, fun game of spinning plates, with an ending that's a bit too silly for me. But this is an enjoyable, sidewise look at the post-apocalypse.
For more great free experiences, check out our roundup of the best free PC games.