Tetris 99 proved earlier this year that any game can make for a good battle royale, and finally, someone has applied the same logic to Mario. Mario Royale is a fan-made project by a developer only going by InfernoPlus. It's playable in any browser, and you should probably check it out before Nintendo takes it down.
Hosted on InfernoPlus' site, Mario Royale is simple. You pick a name, bind your keys (either keyboard or gamepad, which is supported), and try to make it to Bowser. All the while, other Marios are doing the same, and while they're not tangible-unless they grab a star-they can still mess your run up by bouncing koopa shells or blocks.
After a few rounds of it, I'm pretty hooked. While World 1-1 is overly familiar at this point, running through it at breakneck pace against a bunch of other players, balancing how fast I'm going against what obstacles they might be throwing my way, is a blast. I've glimpsed Bowser's visage once, and now I'm dead-set on taking a spot on the podium.
Right now, worlds one, two, and three are in the rotation. You can check out more info on InfernoPlus' announcement video (which has some pretty regrettable jokes about Miyamoto, c'mon dude), but you should play sooner rather than later if you're interested.
Previous fan works like Metroid 2 remake AM2R have faced Nintendo's ire in the past, and while this is at least a more original interpretation, it's still World 1-1, Mario, pipes, and castles. It's hard to think it will escape Nintendo's gaze, and the game's creator told Vice as much in an interview.
"I just expect it," InfernoPlus told Vice, when asked if he's worried about a letter from Nintendo. "I anticipate it to happen. If it doesn't, it's great. But it's more likely to happen. I'd say it's 50/50, maybe more, because it got so big all of a sudden. If it does, I can just re-skin it."
InfernoPlus is looking at other small improvements, like disabling all screen names so Twitch streamers won't have to worry about banned words popping up on the winner's podium. But otherwise, we'll just have to enjoy the time with Mario Royale while it lasts.