Space Defender Xtreme is a free arcade space shooter game developed by Scratchmark for Android users. The game's objective is to defend Earth from hordes of alien attackers, and it offers endless retro arcade-style gameplay.

Players can choose from various unique space crafts, each with its advantages and disadvantages. As the game progresses, the alien enemy types get gradually more difficult, and players can switch between different weapon types. There are also boss levels that get significantly harder each time, adding to the challenge.

To help players out, they can collect Shield, Weapon, and Health power-ups to combat the ever-increasing might of the enemy. It's worth noting that while shields and weapon battery recharge, health does not.

One of the best features of Space Defender Xtreme is the global stats and leaderboards, which allow players to compete against others worldwide. It's a simple, honest, and 100% free gaming experience that doesn't have any ads or in-app purchases. Overall, Space Defender Xtreme is an addictive and challenging arcade game that's perfect for those who love retro-style shooters.