Star Defender 4

Star Defender 4 was one of those games you'd find in the later days of the Flash era, a straightforward top-down shooter. It came out in 2008, developed by a studio called Skyworks. You loaded it up in your browser, and it was just there, ready to play without any fuss.

You control a lone ship at the bottom of the screen, moving it side to side with your mouse. Waves of alien craft descend in patterns, and your job is to clear each wave before they reach the bottom. You fire your main gun by clicking the mouse, and you can hold down the control key to unleash a more powerful secondary weapon with limited ammunition. The pace is steady, methodical; you learn to track multiple targets and manage your special weapon for the denser formations. It feels like a focused, almost rhythmic exercise in clearing the screen.