I know, I know. Singleplayer co-op. Bet you thought that was a typo. Just stick with me. Shattered Realms is a 2D brawler whose free demo supports up to two players. So you could play with a buddy, or you could play alone and control two of your chosen character at the same time. The second character acts like a shadow, mirroring your moves in perfect harmony, and is handily the game's most distinguishing feature.
That's not to say the rest of the game is just average, mind. It looks, sounds and plays great, with perfectly punchy sound effects and screen shake on attacks. The Shattered Realms demo comes with three characters, as well as three sponsors who give different bonuses. There's an arcade campaign, a training room to brush up on combos—of which there are many thanks to the game's intuitive skill cancelling—and a versus arena where you can pummel your friends.
It's quite hefty for a free game, that's for sure. Developer Kopskop says the current version was made in around six months, and development may continue if there's enough interest in the game.
Shattered Realms can be played with a keyboard, but I strongly recommend using a controller. It supports Xbox One and Logitech controllers natively, but it also works with a PS4 controller. If you're wondering how to use your PS4 controller on PC, check out our guide. One more tip: don't alt-tab out while playing, otherwise the game may register your shadow as player two rather than your shadow, meaning you'll lose control of your double.
You can get Shattered Realms for free on Itch, and you also have the option to donate up to $10 to developer Kopskop. And if you're looking for more brawlers, have a gander at the best games in the Humble Brawler Bundle.