One of the most common practices in fan-made gaming is putting characters from one game into another game. We have seen Sonic in Mario games, Megaman in Contra and even Ryu Hayabusa in Bionic Commando. But one fan made game turns this dial up to 11. It puts all your favorite video game characters in all your favorite video games at once! It’s Mushroom Kingdom Fusion, and it’s probably the craziest Mario game you ever played.

Mushroom Kingdom fusion started as a simple project. The idea was to make a Mario game in which Mario has access to all of his power-ups. That’s the fire flower, the tanooki suit, the cape, the bunny ears from Super Mario Land 2 and even the blue shell from New Super Mario Bros. He would have all of his moves from other Mario games, including spin-jumping, high jumping and even picking up and throwing things from Mario 2.

Things got crazier from there, however. Soon, the team started making their own power-ups. Now Mario could get suits that turn him into Duke Nukem, or a Street Fighter character, or even give him Spartan armor from Halo. The team also split up the game into multiple characters, allowing each to play slightly differently. Soon, every character had their very own exclusive power ups, and the current incarnation of Mushroom Kingdom Fusion was born.

At the beginning of the game, you only have access to Mario and Luigi. As you play through the game, however, you’ll unlock Wario, Sonic, Tails, Arthur, Kirby, Link, Samus and Roll to play. In addition, there are a number of secret characters you can find like Simon Belmont, Ryu Hayabusa and even R.O.B. the Robot. The main power-ups in the game are the Super Mushroom, Fire Flower, Raccoon Leaf, Tanuki Suit, Hammer Suit, Sci-Fi Suit, Mega Man Suit, Blue Shell and Soldier Suit. Each power-up effects each character slightly differently. For example, the Fire Flower gives Mario his iconic bouncing red fireballs, while it gives Luigi his Super Smash Bros. straight green fireballs, and the Raccon Leaf gives Mario his iconic Raccoon Tail, while it turns Luigi into a Mario Land 2 bunny. All of these power ups have even stranger effects when used on other characters, such as giving Link his boomerang, or giving Sonic and Tails the flame shield from Sonic 3.

But the best parts of Mushroom Kingdom Fusion are the stages. You’ll travel through all sorts of worlds themed around Castlevania, Contra and incredibly old Atari games. From time to time, you'll face off against bosses from modern day video games, as well as classic bosses from video games past. There might even be times where you fire rocket launchers at zombies, use mini-guns against invading aliens and run through Smash Bros. bonus levels. It’s a huge mash-up of every type of game that you know and love, and it’s just dripping with nostalgia.

Mushroom Kingdom fusion is free to download for the PC. It is currently at version 0.5, and is still being updated, although it is currently on hiatus. The team is also going on to work on another game, Super Mushroom Fusion. For more information, head on over to the official project website and forums.