Alien Syndrome is played as a top-down shooter, with players turning their characters the direction they would like to shoot. The game has 40 levels, with 5 bosses and 15 mini-bosses. Players customize their character to expand in-game strategy options.
Alien Syndrome has 80 different weapons to use and hundreds of armor types as well as bonus items. Players are accompanied by a robotic drone (SCARAB) that serves as a storage space for items as well as a backup for the main character. As a constant companion, SCARAB can assist in fights and grant on-demand access to the character's cache of weapons and armors. Players have both a life meter and a constantly refilling energy meter, with the latter reflecting shield power. The game also features co-op multiplayer for up to 4 people on one screen for the Wii version. On the PSP version, the game features co-op multiplayer via a
WiFi connection. On the PSP, player movement and aiming use the analog stick; while a player is firing a ranged weapon, her facing is locked. On the Wii, movement is handled by the analog stick on the Nunchuk, while aiming is controlled by pointing with the Wii Remote. The Wii version emphasizes use of the Wiimote. Tilting the Nunchuk rotates the screen to change orientation. In addition, motion control-based minigames are available to the player to increase stats via DNA augmentation chambers found in various levels, defeat lock protection on golden chests with guided nanites to procure items with a variety of attributes as well as loot, and disinfect rare items afflicted by the Alien Syndrome with charged nanites to restore their attributes. ==Reception==