There have been half a dozen official iterations of Smash Bros. over the years, but some folks just love the classics, as there’s a very dedicated community of players who still consider the original Nintendo 64 release of the game to be their favourite. However, if you want to play some competitive Super Smash Bros. these days, you previously only had two options: lug a Nintendo 64 console to a friend’s place, or endure the hellscape that is delay-based netcode via an emulator.
Thankfully, there’s now a third option: RMG-K, a fork of the original RMG Nintendo 64 emulator that just received a v0.9.4 update on May 14. The update doesn’t just allow you to play Super Smash Bros. with rollback netcode, though–it allows you to play any multiplayer Nintendo 64 game with rollback netcode, and the results are incredibly impressive.
If you’re wondering why this is a big deal, fighting games are a nightmare to play when using standard, delay-based netcode. For a lot of competitive games, using delay-based netcode usually isn’t a big deal, but when two frames can make the difference between connecting a hit and eating a twenty-minute-long combo, it’s just not up to scratch.
This might look like abysmal dogshit, but this is demonstrating 4f rollback netcode for 64 at 320 ping (You would need at least 10f for kaillera/delay based)
Grab the early PoC build below!https://t.co/kRDL3uoHe0 pic.twitter.com/DwKlwFH4ZV
— NyxTheShield (@NyxTheShield) May 8, 2026
Rollback netcode, on the other hand, is straight up wizardy. I’ve been playing fighting games since I was a kid, and it still impresses me to this day, as rollback netcode essentially predicts what the most likely input will be in a given situation, and, as the name implies, rolls back to a previous frame if it gets it wrong. Unlike delay-based netcode, this allows for incredibly smooth matches, even if you’re not using a wired connection.
The rollback update for RMG-K was developed in tandem with the original author of the RMG fork on GitHub, Jay-Day, but the main star of the show here appears to be NyxTheShield. You may have heard of NyxTheShield through their other, much more highly publicised work as a composer, as their work can be heard in the extremely popular Undertale fan series Glitchtale and Underverse. I’d wager that even if you haven’t watched either series, you’ve probably heard this banger at some point.
Turns out they’re an incredible coder too, though, although maybe that’s not too much of a surprise, as I’m pretty sure the Venn diagram of Undertale megafans and people who are interested in coding is a flat circle.
Funny thing is, even though the RMG-K page states that this enables rollback netcode for all Nintendo 64 games, it’s been difficult to verify how well it works with other games…because everyone only seems to be interested in testing it out on Super Smash Bros. That being said, I did see someone in the SSB 64 Discord say that it works great with Mario Tennis, so that’s something at least.