^linked video is of a nice mountain run in Rigs Of Rods
I know everybody always talks about BeamNG, but Rigs Of Rods is fully open source, free and still in development! It isn’t rapid development, but I feel like this game is mature enough as a sandbox that this shouldn’t be a priority for players deciding whether to try out Rigs Of Rods or not. This game has been around for a LONG time and there is a lot of custom vehicles for it that had a lottt of care and love put into them that makes this game worth checking out beyond any considerations for how quickly features are progressing. I really hope that Rigs Of Rods becomes more broadly appreciated.
The graphics aren’t amazing but you know what… that makes Rigs Of Rods a great game for a Steam Deck or similar Linux handheld!
For similar Free and Open Source Linux racing fun check out the great Stunt Rally, it has splitscreen!