The latest free update for 5 Live Studios’ Satellite Reign, the spiritual successor to Syndicate, allows the entire campaign to be played cooperatively by up to four players. Even better, Satellite Reign is available on Steam until July 28th with 50% off.
Multiplayer is supported cross-platform for any combination of PC, Mac or Linux, and supports internet or LAN play. Up to 4 players can divide control of the game’s 4 agents between them as they choose, and players can drop in and out at any stage. You can even switch between single-player and multiplayer within the same campaign.
Here’s a gameplay trailer from last year -