Smash Bros. is, at its very core, a multiplayer experience. The game loses something when you’re playing by yourself. Over the years, Smash’s developers have tried different ways of offering a solo experience, like story modes, to varying degrees of success. But Super Smash Bros. Ultimate, which launches tomorrow on the Nintendo Switch, has finally cracked the code. The game introduces a new “spirits” mode, which, while initially very confusing, actually manages to turn the frantic fighter into something approaching a single-player role-playing game.

It has everything you’d expect from the genre: equippable gear, lots of battles, and a melodramatic story. And it’s fantastic.

It all starts out with a very intense opening video, in which virtually every character in the game — all 70-plus of them — is captured. Their spirits are then removed from their bodies, which, in turn, are operated by sinister beings for battles. There’s only one survivor: Kirby. You take on the role of the cute pink ball, with the goal of rescuing your fellow video game mascots from the clutches of evil. It’s like the Avengers, but slightly more anime.

The “spirits” name is derived from one of the new gameplay features introduced in Ultimate. Spirits are, essentially, characters that you can collect and equip, giving your main fighter different characteristics. It’s all very weird and convoluted at first. As Kirby, your quest comes in the form of a series of battles, each one with a different set of rules. At one point, you’re fighting a gigantic form of Bowser, and the next, you need to find and defeat an incredibly tiny version of Mr. Game & Watch. After some of these battles, you’ll rescue characters who then join your roster of fighters. But you’ll also get spirits, which are characters but not ones who actually fight.

Instead, think of spirits as gear: you can equip a few at a time, and they do things like increase your strength or defense, or offer unique abilities like a floatier jump. You can also level up spirits over time, and different kinds of spirits are more useful against different kinds of enemies. It’s the sort of rock-paper-scissors gameplay that Pokémon fans will be familiar with. The result is that, much like in Diablo, you’ll be constantly gaining new gear, and constantly changing what you have equipped to better suit the situation. (The game will recommend loadouts for each battle, making this much less tedious than it sounds.)

Now, this could’ve just been a series of battles with unlockable gear, and it still would’ve been pretty fun. But virtually every aspect of the adventure is tuned to make it feel like an RPG, only with Smash fights in place of turn-based battles. You move around an expansive map, for instance, one with different regions, all based on a different Nintendo franchise. You’ll pilot a hovercar around an F-Zero race track and delve into the fiery darkness of Bowser’s castle. And it’s all rendered with an art style reminiscent of an old Dragon Quest map. Along the way, you’ll encounter a range of RPG staples: shops to buy useful items, hidden treasure chests, and dojos to train your spirits. And the structure forces you to experiment, using different fighters and spirit combinations to tackle some of the trickier battles.

It’s a cohesive package that stands on its own: it’s not just a fun diversion for when there’s no one around to play with. Instead, spirits is a big, meaty adventure to dig into that offers a completely different way of enjoying Smash. It combines two things that don’t immediately seem compatible, and it will give you a whole new appreciation for Kirby.