Twitch Sings, the first game developed in part by Twitch, is out now.
It's a free livestream karaoke game co-developed by Rock Band and Guitar Hero studio Harmonix Music Systems. It has nearly 2,000 songs to choose from, and they're all "in the style of" cover versions rather than the original tracks. The game analyses how well you're hitting notes, rewarding you with loads of XP for a pitch-perfect performance.
Audience interaction is at its core: viewers can request songs, vote on the next track, challenge the streamer to a sing-off duel, or set specific challenges—the example challenge on the game's website is "sing with your tongue out".
You can duet, but you can't do it live. Instead, one player can record half of the duet, upload it, and then their partner sings the other half over the recording.
Because it's built by Twitch, you can stream directly to the platform without having to use streaming software such as OBS. You can customise your on-stage avatar and change the backdrop for your performance, and you pick tracks from a library of songs organised into playlists, such as "easy to sing".
If you don't want to go on camera, you can just display an avatar. You don't have to sing live, either: you can record your performance, tweak some of the audio levels, and then upload the footage. You can even just keep it all offline and play solo, but it's really designed for an audience.
In an FAQ for the game, Twitch says it might add paid features in the future, but doesn't say what those features might be.