What Stream Racer is
Stream Racer is a racing game built around Twitch.tv streaming. You build your own tracks, host races on them, and stream the whole thing so your viewers can take part. The game is in Early Access and covers casual racing and simulation, with a minimalist look and a third-person camera. It is described as a relaxing, funny and atmospheric racer, so the focus is on a laid-back session that turns chaotic once the cars start piling up.
How a group plays it together
The core loop is yours as the host: you design a track, start a race, and hand out cars to the people watching your stream. Viewers join the race you are hosting, which turns your audience into the field you are racing against. Online PvP is the competitive side of it, so the fun comes from a full grid of real people rather than a set of scripted opponents. The chaos the store text mentions is the point — a stream full of viewers all driving at once is meant to be messy and entertaining for both you and them.
Before you start
You need a track before you can host anything, so expect to spend time in the level editor first. The editor is one of the game's tags, and building tracks is presented as a normal part of the experience rather than an extra. Since the game is Early Access, features and content may still be in progress while you play. It also carries the Singleplayer tag alongside Massively Multiplayer, so you can drive on your own tracks when nobody is joining. The game is Free To Play, so getting a race going with your viewers does not require anyone to buy in first.