All Super Mario Advance series games and Mario & Luigi: Superstar Saga all feature a remake of the original arcade Mario Bros. This is technically a full game in itself, so your mileage may vary if it should count as a "side mode," but I'm counting it. The Mario Bros remake is hands down the best way to play that game to date, and even features what seems to be a well-made multiplayer mode (though I haven't played it). If you have the GBA Mario games available to you in some way, definitely try the Mario Bros remake if nothing else.

There's not necessarily a "main" mode to Melee - or any Smash game, for that matter. However, I think some things like Events or Break the Targets can count as "side modes" for sure, and they're all great.

WarioWare games in general has a plethora of minigames to pass the time if you don't want to play the microgames, and a large variety of them. WarioWare Inc. definitely has my favorite of them all, though, in the form of Dr. Wario.

...It's literally just NES Dr. Mario with different music and visuals, it's amazing.

I'm not gonna include the other WarioWare games because they've all got a bunch of their own side modes, but they're a gold mine for side mode enjoyers such as myself.

Mario Party 5 is my favorite game in the series. That is partly because of the main party mode, but it's also partly due to the amazing side modes of this game. To me, great side modes are as necessary a piece of Mario Party as the minigames and board mode is, and this game nails it. A mode where you basically play an actual board game, a singleplayer story mode, a full-on mech battle game, and multiple minigame modes.

I used to rent this game fairly often, and my favorite part were the special games. Modes inspired by Super Mario Sunshine, WarioWare, Luigi's Mansion, Mario Bros, and Donkey Kong Country, plus those sweet sweet Mario sports games bosses, yes please.

Definitely a weaker lineup of side modes than 5, but still a good time. A solo mode, the really fun bingo minigame mode that I can't believe hasn't returned, some great long-form minigames, and... ok, I would exactly call this good, but there is an extensive microphone mode. A for effort, if nothing else.

Do I even need to say anything? The minigames in this one are incredible, and I still make time to play some whenever I boot this game up. On top of that, there's a decent enough multiplayer mode I used to play with friends, though it's not too much to write home about.

Still not up to snuff with 5's side modes, but we've got good ones again. Another solo mode that really changes up how you play a lot of the boards, good minigame modes, and my favorite: an 8 player mode. When I was a kid, I would play this game by myself a lot, controlling both of my characters with one controller. Yeah... might sound a little sad, but it was a fun time - I imagine a lot of people have never played this mode just because they thought you needed eight people, but you really don't. Try it if you get the chance!

I didn't actually grow up with this game so I think of Mario 64 minigames before this one, but I know most people think of this game first, and it has its own original minigames. The main reason I have this here, though, is actually just because I really like the multiplayer mode, surprisingly fun competition.

I'll just be repeating myself if I actually list it out again. Luckily, the next Mario Party I'll bring up has a lot more interesting side modes.

Your mileage may vary on this, but I consider Subspace Emissary to be the "main" mode of Brawl - I think it's the main reason to play it today. Regardless, this has the best side modes in the series. Events, classic, all-star, various stadium modes, stage builder, and even coin launcher. This game is absolutely loaded with content, and so much of it is so good. I've never really understood why a lot of people don't like this game as a whole. Sure, I get the problems with competitive play, but if you play the casual stuff, there's so much worth playing with this game.

So many inventive, fun, and challenging minigames in this one. Not to mention the Zen Garden which is a comfort mode of mine.

Should I really count the co-op mode for this? It's the part represented in a lot of marketing, is practically the length of the main story, has a story of its own, and was the main focus of DLC.

Oh well, I do consider the singleplayer campaign to be the main show here, which would make this a side mode. Up to you if that should really count, though.

I would die for the multiplayer.

Seeing specific character endings in fighting games is always a highlight for me, though the main reason this is here is because of the S.T.A.R. Labs Missions, basically the Smash Melee event mode but each character has their own basic story. They tried to replace this mode in Injustice 2 with a multiverse mode... it was neat, but much harder to get into.

A specialized version of the story where you play as Dedede, the origins of the Kirby Fighters subseries, a rhythm game that I have a hard time with but has still fun, and two arenas. These side modes are part of why this is my favorite traditional 2D Kirby.

HowLongToBeat has this game's completion listed at 365 hours. I think that says enough.

Really, though, I've barely touched this game's side content but there's so much of it and so much work was put into it, I need to have it on this list.

Kind of hard to tell what the "main" mode of this game is. Just the plain Dr. Mario mode, or the preset puzzles you can play. Doesn't matter either way, though, because Virus Buster is why this game is on here and is why I have hundreds of hours into this game.

Quite similar to Triple Deluxe. Story mode with Meta Knight, the origins of the Kirby Clash subseries, the smaller version of the excellent Kirby Blowout Blast, and, again, two arenas. Great time.

You might have been wondering where the Mario Kart series had been on this list cause it's had an established and well-liked side mode since the first game in the form of battle mode. Simply put, I didn't want to have to put every Mario Kart on this list. This game has all or most of the previous entries' battle modes, plus new ones. Having one of the courses being a Splatoon crossover is cool, too. Main complaint is that I think there could be more courses, and it kind of stinks that the Wii U battle mode is completely dropped - that mode isn't better by any stretch, but was fun in its own right.

I forgot about mission mode! The only real reason I go back to this game, and I mode I wish would return. It did for Mario Kart Wii, but it's now defunct, and it more or less has for Mario Kart Tour, but it's also just part of the main game there.

Much like Mario Party 5, I love this game partly because of the main party mode, but also party because of the amazing side modes. This game is such a good package and extremely overlooked. A frenetic and fun mode called Coin Rush, a simple but decent board game mode, a second party mode that might be better than the main one, and a puzzle tower mode that's super addicting. There's also an original puzzle minigame which has been a series staple since MP3, though I haven't played it, and an admittedly bad rhythm mode. There's so much to this game, I wish it got the attention it deserved.

Whenever I hear people say this isn't a good game, I know that they're fake fans that ONLY play the main party mode. Granted, that mode could indeed be better, but there's a lot to love about this game outside of that. A whole other party mode that's an adaptation of Star Rush's party mode that honestly is so much better than Super's main party mode, River Survival is a very fun co-op mode, an actual good rhythm-based mode, more minigame modes, and while I haven't played it, there is another mode that offers unique games if players have multiple Switches and multiple copies.

...You can see why I haven't played that mode yet.

Kind of lacking in good side modes, but Smash Run is a very good mode that absolutely needs to come back. I'll still play this game from time to time just for it.

Smash Tour is much more fun than anybody gives it credit for, and I am tired of the slander. On top of that, there's a lot of events, a fun all-star mode, and some neat new modes in the form of Master and Crazy Orders.

I am not the first or last person to say this game's side content blows. But at least this is the best classic mode in the series.

The Pikmin series is quite notable for its side modes with a fun, arcadey challenge mode in the first game, and a massive challenge mode in the second one. But I haven't really played much of those modes which is why I didn't add them to the list.

But what I have played extensively is Pikmin 3's side modes. Deluxe introduces two short but awesome side stories. But then there's mission mode proper which is among my favorite things to play in any video game. An insanely skill-testing challenge with the Find Treasure mission. Defeat enemies is usually pretty easy, but is always fun and with a couple of intense missions. And then there's the Defeat Bosses minigames which are... just the story mode's boss fights and that's it, so pretty negligible and easy, but fun.

There's also bingo battle which looks likely an incredibly fun multiplayer mode with way more maps than you'd expect. But I unfortunately have never had a second player for this mode, so I have yet to play it. Shame it wasn't online.

To put it bluntly, the side content of Pikmin 3 (Deluxe) singlehandedly made it my favorite game in the series before Pikmin 4 came out - and even then, it's such a close competition.

Minigames that will make you poop.

Ok, so I didn't really know how I wanted to approach Sonic side modes on this list, so consider this my master Sonic entry.

Sonic Adventure 1 and 2 feature the Chao Garden which is a mode I never really got into, but it's very detailed and is kind of the reason a lot of people even like these two games. I prefer the main mode, but it's still a good time.

Sonic Adventure DX has an interesting mission mode which I haven't really played much, but I find quite interesting. The GameCube version features every single Game Gear Sonic game which is kind of cheating to count, but is such an amazing bonus.

Sonic Adventure 2 Battle has an addictive competitive multiplayer mode.

Shadow the Hedgehog has a multiplayer mode I played a lot of as a kid with my cousin.

Sonic and the Secret Rings is the biggest one, though, with a whole-ass Mario Party rip-off in it as a side mode. I haven't played this mode in many years, but I loved it as a kid and I think I would still like it.

This game features dozens of challenges in a dedicated challenge mode. I haven't done all too many of them, but they honestly really do push your Mario skills, asking for near perfection to get gold medals. It can be frustrating, but fun!

Since this week (as of typing this) is the first time I've played this game, I've had little experience with Ape Escape and didn't really get into the side modes. But I gotta say, if I grew up with this game, I would have dumped hours into it. There's a surprisingly in-depth skiing game, a weirdly-controlled but fun and goofy boxing game, and best of all a monkey space shooter. I actually did put ten or so minutes into that one, I think it'd be a blast with a second player. Kid me would have had a field day with these.