RED ALERT

Room: Multiplayer: start, choose Multiplayer Game → Network. One player clicks New, the others pick that game and Join. Everyone with the same invite link is in the same room.
Command & Conquer: Red Alert (Westwood, 1996) running in the browser — built from EA's GPL source via Vanilla Conquer and Emscripten (source). Game data from EA's 2008 freeware release. Best with mouse and keyboard; on touch screens: tap = click, drag = select, hold = right click, two fingers = scroll the map. Saved games stay in this browser.