Mayhem Intergalactic is a game with simple rules giving rise to rich strategy. Each session lasts only 5-15 minutes, yet there is enough depth and replayability to keep you occupied for hours at a time. In a nutshell, it's a turn-based 4X-like strategy game, providing a streamlined version of the gameplay found in other turn-based strategy games. There is no resource micromanagement, allowing you to concentrate on strategy and tactics instead. Also, there's an alien wearing a monocle.
This is a free feature-limited demo with no time limit or usage limit. It showcases the Quick Start singleplayer mode and has restricted multiplayer capabilities. To install, simply run the .exe installer and follow the instructions.