StarJack.io is one of the best free-to-play online multiplayer Io games. It leads you to a cool combat set in space. In which, you need to conquer the fast-paced tactical strategy by capturing the most homeworlds. So, you should master how to send your fighters and build more people in a short time. To progress, do not ignore linking planets for defense bonuses. Not only that, you will have the chance to test various useful abilities during your adventure. Good luck!
Instructions: Use LMB or choose WASD/Arrows to move the map. Shift+LMB to deploy 50% fighters, RMB to cancel the command, Space to snap to a homeworld, Tab to view stats. Press LMB on the source planet and click the target planet to send all fighters.