OpenTTD is an open source simulation game based upon Transport Tycoon Deluxe

What made OpenTTD a great success that it's playable out of the box. Most open source game remakes [0] are engine-only and you still need the graphics, arts, sound, and music assets to make it a 100%, and actual playable experience. OpenTTD started like that too but from the very beginning it was a goal to "detach" the game from the original as quickly as possible. It was released in 2004, the actual graphics replacement project started in 2007 and by 2009 100% of the sprites were finished so the original game files were not needed anymore [1]

And actually there are now 5 different basesets on top of the original TTD one [2]

It also made possible things like releasing the game on Steam and GOG.

0, https://github.com/radek-sprta/awesome-game-remakes

1, https://wiki.openttd.org/en/Archive/Community/Graphics%20Rep...

2, https://bananas.openttd.org/package/base-graphics

I was about to ask if the proceeds of the Steam version go to the OS project, but I see it's free-to-play. I should get it that way, it's convenient and auto-updates and the like, and they will get good statistics from Steam that way.

But also I have a backlog of games I still need to finish, including ones that scratch a similar itch like Satisfactory and Factorio.

If you like Factorio, it's worth trying Dyson Sphere Program as well.