The game displays a dynamic crosshair, positioned with mouse movement, with which to aim. Move the point of intersection onto an enemy to establish target locks. Locks are indicated by semi-circular lines that close in around the enemy being targeted, and the number of locks established is indicated by small gray triangles above the lock. Locks accrue one-by-one until the maximum number of eight (8) per enemy is attained, or until the number of locks required to destroy the enemy have been accumulated. The lock around an enemy turns red when the number of locks required to destroy the enemy have been established.
Control is with the mouse for targeting as noted above, and the space bar is used for firing. All targets locked-on are fired upon with once press of the space bar. You can press [B] to cancel locks targeted. This may be useful since later enemies will fire at you when you lock-on them. By canceling targeting, you can therefore aim at only the shots fired at you and rack up more points by repeating the process.