It's not an emu specifically, you download the game client for your particular OS (Linux in my case) and run the app and it'll ask you to drag and drop a Super Mario Bros. nes rom into the game Window (literally drag and drop the rom) and from there you're good to go. Just download the client for your OS and then the SMB rom (just a search for NES roms on Archive.org and you'll find the Super Mario Bros. (world) rom). I don't know how Hexbear feels about rom links but if you need me to I can DM you the direct link for the rom ;)
Huh, hadn't heard of Old School Rally. I'll have to check it out. Yeah, New Star is fun, but I do find the crew management stuff boring and slightly tedious. Overall it's a solid racer. I did notice on the expert difficulty I was just getting smoked no matter how good I was driving, so I bet the crew management and upgrade stuff is even more necessary for playing elswise I have no clue how expert is winnable. Formula Legends sounds familiar but I couldn't tell you where I heard about it from.
Actually RBR is super easy to get running on a Win machine now using the Rally Sim Fan's version of RBR here: https://www.rallysimfans.hu/rbr/download.php?download=rsfrbr
In the last half dozen times I've never had an issue on Windows and it has great community support for mods and online play. Seriously, if you haven't tried it I highly recommend it, seriously the GOAT rally sim even twenty years later. There's also a couple other modern implementations of RBR as well that update the graphics and provide other tools too.
My dilemma is I only run Linux yhese days and am too lazy to implement a dual boot for just one game when 80+% of stuff works just fine for me through Lutris....although I have been tempted to because RBR, especially yhe Rally Sim Fan version, is just that damn good.
"Then I jumped out of the bushes and was like 'Raaaawr' and she kicked me in the nuts and called the cops."
Heads up, the Nightmare Alley link goes to Problemista
Oh yeah, getting the RBR setup to detect the right and left triggers as seperate can be a pain I remember, but as far as I know even that has a fix now.