Aim with your mouse / light gun / finger. Click, tap or squeeze the trigger to fire. R or the on-screen prompt reloads. Headshots score double. Shoot the thrown axes out of the air. Crates drop hearts. Don't let anything reach you.

Got a camera watching the couch and an LED on the gun? Hit "Set up camera aim" below — one-time colour + corner calibration, then the gun drives the crosshair directly. Trigger still needs a real click (an Arduino wired as a USB mouse button works great). Press C anytime to flip between camera aim and plain mouse.